Applied Urban Sound Planning

Abstract

Worldwide, cities are expanding at an unprecedented rate. Population growth in city centres places unprecedented demands on existing city infrastructure systems that are bringing many EU cities to a breaking point.
Traffic noise, people noise, pollution, poorly planned and managed places within our cities threaten the health and wellbeing for all of us. Large scale and well-planned infrastructure developments are therefore needed to face this challenge.
The requirement to improve people’s mobility within cities will increase, which inevitably affects the urban infrastructure, resulting in the expansion of the transportation networks. Consequently, negative impacts such as noise and air pollution are expected to rise. In order to meet these challenges, the integration of urban and transport planning will be fundamental to the future of successful cities. The delivery of collaborative transport, public realm and regeneration projects can achieve this. It has therefore never before been more important for technical, social and ecological systems to work together.
In such a dynamic environment, the newly established discipline of Urban Sound Planning combines synergies with the other planning processes in a unique way. The Urban Sound Planner brings a different perspective and contributions to the process of delivering well-designed cities that work for people rather than harm them. This is achieved by improving the quality of sonic urban environments, not simply trying to make things quieter, but proactively designing to avoid noise generation and defining policies and strategies to value, introduce and preserve the characteristics of a good sonic environment.
Presently, the main objective of an acoustic intervention is defined in the regulations as a noise ceiling and is usually considered after the urban plan project is already decided, limiting the opportunities of approaches to other than traditional engineering noise control. This approach is usually restricted in space (to the most exposed receivers) and in time (short-term perspective), missing the opportunity to contribute to improved environments, sometimes missing to take advantage of high-quality potentials. The holistic approach of SONORUS to urban sound planning relies on preventing the occurrence of noise, by not limiting the interventions to the obvious noise engineering solutions but to include a combined approach that coordinates actions of different acoustic fields to provide an integrated solution.
In this Chapter, we are summarizing examples where urban sound planning is applied within the SONORUS project. The intention of including practical cases in the project is to develop exemplary application to real case scenarios within the urban sound planning approach. This work aims to contribute to improving the current situation and reversing the growth of poor urban sound environments. Four different scenarios are included, varying in scales, methods and outcomes: Rivierenhof Park in Antwerp (Belgium), Frihamnen area in Gothenburg (Sweden), Valley Gardens in Brighton & Hove (UK) and the Colosseum, Palatine and Roman Forum area in Rome (Italy).

Full text

Applied urban sound
planning
Authors: Sónia Alves, Laura Estévez Mauriz
Contributions to introduction: Matthew Easteal
Contributions from working groups:
Antwerp: Gemma Maria Echevarria Sanchez, Efstathios Margaritis, Karlo Filipan, Sónia Alves
Brighton & Hove: Francesco Aletta, Raúl Pagán Muñoz
Gothenburg: Laura Estévez Mauriz, Georgios Zachos, Sónia Alves
Rome: Virginia Puyana Romero, Fotis Georgiou, Ignacio García Merino, Mercury Kounturas
Worldwide, cities are expanding at
an unprecedented rate. Population
growth in city centres places un-
precedented demands on existing
city infrastructure systems that
are bringing many EU cities to a
breaking point.
Trac noise, people noise, pollution,
poorly planned and managed places
within our cities threaten the health and
wellbeing for all of us. Large scale and
well-planned infrastructure develop-
ments are therefore needed to face this
challenge.
The requirement to improve peo-
ple’s mobility within cities will increase,
which inevitably aects the urban in-
frastructure, resulting in the expansion
of the transportation networks. Conse-
quently, negative impacts such as noise
and air pollution are expected to rise.
In order to meet these challenges, the
integration of urban and transport plan-
ning will be fundamental to the future
of successful cities. The delivery of col-
Introduction
69

laborative transport, public realm and
regeneration projects can achieve this.
It has therefore never before been more
important for technical, social and eco-
logical systems to work together.
In such a dynamic environment, the
newly established discipline of Urban
Sound Planning combines synergies
with the other planning processes in a
unique way. The Urban Sound Planner
brings a dierent perspective and con-
tributions to the process of delivering
well-designed cities that work for people
rather than harm them. This is achieved
by improving the quality of sonic urban
environments, not simply trying to make
things quieter, but proactively designing
to avoid noise generation and dening
policies and strategies to value, introduce
and preserve the characteristics of a
good sonic environment.
Presently, the main objective of an
acoustic intervention is dened in the
regulations as a noise ceiling and is
usually considered after the urban plan
project is already decided, limiting the
opportunities of approaches to other
than traditional engineering noise con-
trol. This approach is usually restricted
in space (to the most exposed receivers)
and in time (short-term perspective),
missing the opportunity to contribute
to improved environments, sometimes
missing to take advantage of high-
quality potentials. The holistic approach
of SONORUS to urban sound planning
relies on preventing the occurrence of
noise, by not limiting the interventions to
the obvious noise engineering solutions
but to include a combined approach that
coordinates actions of dierent acoustic
elds to provide an integrated solution.
In this Chapter, we are summarizing
examples where urban sound planning
is applied within the SONORUS project.
The intention of including practical cases
in the project is to develop exemplary
application to real case scenarios within
the urban sound planning approach. This
work aims to contribute to improving
the current situation and reversing the
growth of poor urban sound envir-
onments. Four dierent scenarios are
included, varying in scales, methods and
outcomes: Rivierenhof Park in Antwerp
(Belgium), Frihamnen area in Gothen-
burg (Sweden), Valley Gardens in
Brighton & Hove (UK) and the Colos-
seum, Palatine and Roman Forum area in
Rome (Italy).
DIFFERENT SCALES, DIFFERENT
NEEDS, DIFFERENT TOOLS
The holistic approach has the ability to
assess the sonic environment at dierent
urban scales, from growing mega-urban
developments to the small urban park.
Mega (more than 10 million inhabitants)
or Meta cities (more than 20 million
Urban sound planning - the SONORUS project
70

inhabitants) are in a growing trend and
by 2050 the number of megacities is ex-
pected to rise to 41. However the pres-
sure it adds in terms of urban infrastruc-
ture demand is enormous: the increased
need to commute from peripheral areas
into the city centre will add even more
trac resulting in increased pollution and
lower quality of life. History has shown
that building more road infrastructure
will only increase trac. In order to cope
with this previously unseen demand
for mobility, innovative and integrated
approaches are required. Ecient public
transportation systems and functional
and safe paths for pedestrians and cy-
clists will support a sustainable mobility
and, at the same time, contribute to the
improvement of the sonic environment.
Specic innovative tools developed
for the analysis of sonic environments
can be integrated into the overall plan-
ning at this level, contributing to an
optimized solution. For both macro and
mesoscale planning of the built envir-
onment, urban sound planning shall be
applied at the beginning of the planning
process. This is the only way to obtain a
coherent solution. Within the SONORUS
project, several tools have been devel-
oped attending to the dierent urban
scales. At the mesoscale or larger, a com-
prehensive and truly holistic approach
can be applied to set the basis for a
good acoustic characterisation of envir-
onments and support future planning
strategies. This may include: dynamic
noise map tools, contributing to an opti-
mization of the trac layout (Gothenburg
test site); integration of noise engineer-
ing concepts, protecting inhabitants from
high noise levels (Gothenburg and
Antwerp test sites); and preservation of
public spaces at a larger scale by means
of soundscape analysis (Antwerp and
Brighton & Hove test sites). In a micro-
scale planning level, the focus is nar-
rowed down to the users, the residents
and their wellbeing, e.g. through the
development of multisensory perception
tools including visual and aural stimuli,
allowing for testing dierent scenarios
(Rome and Brighton & Hove test sites).
Here, small projects take into account
the individual needs and try to improve
the liveability of spaces, promoting in-
teractions between people, in safe and
healthy environments.
It is extremely important to remark
that all scales are inuencing each other.
For that, we must extend the acoustic
interventions to exploit all the potential
benets to obtain a good sound envir-
onment, even when noise has not come
up as a matter of concern. Therefore, the
use of available tools and the develop-
ment of new ones will ensure a proactive
urban sound planning approach.
Applied urban sound planning 71

Map of Antwerp
(Rivierenhof park
marked in green)
Highway on the west side of the park, with
the only connection between the city
centre and the park being the
Turnhoutsebaan bridge
Road that
crosses the
park, dividing
it in two parts
Highway running
on the south side
of the park
1
2
3
4
Urban sound planning - the SONORUS project
72

ANTWERP
PLANNING GOAL: Improve the access and
use of a park area.
MAIN RESEARCH TOPIC: Controlling the
sound environment through noise pre-
diction methods and soundscape of
urban parks.
Mesoscale level
OUTPUT: Impact study of measures to
control the sound environment by FDTD
calculations (nite-dierence time-do-
main) and further development of a
model for human perception of environ-
mental sounds and its translation to an
articial sound perception model.
Description
Antwerp is one of the most populated
cities in Belgium located in the centre of
several road infrastructures connecting
Europe. Road trac and the associated
noise and air pollution are major envir-
onmental challenges for the city.
The study area in which the urban
sound planning praxis is applied in
Antwerp is composed of four sub-areas
aected by a road infrastructure node
situated at the northeast part of the city
with intense trac that combines two
major road infrastructures and a ring
road with local roads.
AREA 1: Spoor Oost is the location
chosen to place a major funfair
(Sinksenfoor) that happens every year in
summer. During the rest of the year this
open space is expected to be a pleasant
meeting point for the nearby residents.
AREA 2: Hof ter Lo is a residential
development exposed to high noise lev-
els. The city asked for several guidelines
and a series of actions to protect the
residents.
AREA 3: Rivierenhof Park is one of the
most important green areas of the city,
however, the park is aected by high
noise levels due to the busy highway
that surrounds the park on the south
and west sides. Additionally, a local road
divides Rivierenhof in two parts.
AREA 4: The Turnhoutsebaan bridge is
the only access to Rivierenhof Park from
the city centre. It is of remarkable impor-
tance, since the area located to the west
of it lacks green areas. A few hundred
meters of roads (the Singel-Ringway) and
a railway separate the two areas. Despite
the spatial proximity, in reality, it is di-
cult to access the park, as the bridge is
extremely noisy, unpleasant and unsafe.
It is mainly working as a barrier instead
of a connector.
Applying urban sound
planning: our study elds
Applied urban sound planning 73

Urban Sound Planning in praxis:
strategies and results in
Rivierenhof Park, Antwerp
- Soundscape design through indivi-
dual perception model, green space and
membership
Dierent acoustic challenges demand
dierent approaches. Thus, in the follow-
ing paragraphs, the main tools applied
at these test sites will be described. The
work is mainly focused on the third area,
Rivierenhof Park.
In order to study the human per-
ception of environmental sounds, the
inuence of green areas, natural sound
sources and relative membership are in-
vestigated. The main strategies used are
based on a soundscape approach. The
idea is to develop statistical and com-
putational models to be used by urban
planners to assess the soundscape of
urban parks. Based on a comprehensive
study, a human auditory attention model
is developed and tested including:
• The conduction of a large-scale
measurement campaign.
• The development of a model for
human perception of environment
sounds and its translation to an arti-
cial sound perception model.
• The application of environmental
sound monitoring at the park.
The rst step of this study was to
gather data in a large-scale measure-
ment campaign conducted not only at
Rivierenhof Park, but also at several other
urban parks in Antwerp. The measure-
ment campaign included the recording
of the sound environment during 22
days with mobile sensor nodes carried
on all paths inside the parks. The re-
corded data included sound spectrum in
1/3-octave bands, audio signals and GPS
position, enabling a spatial representa-
tion of all measurements (Figure 1). At
the same time, visitors of the parks were
questioned about their perception of the
sonic environment.
The outputs of the measurement
campaign include equivalent sound
pressure levels (LAEq) averaged over 1
second along the paths inside the park,
complemented by a comprehensive
characterisation of the sound environ-
ment using several indicators:
• Percentile indicators to get the dy-
namic characteristics of the 1-minute
sonic environment: 50-percentile
to illustrate the average, 90-per-
centile to illustrate the background
and the 10-percentile to illustrate
the high values. The dierence be-
tween C-weighted and A-weighted
levels as an indicator that depicts
the low-frequency content of the
measured sound, as well as the
Urban sound planning - the SONORUS project
74

sharpness, which is a psychoacoustic
parameter that describes high fre-
quency content. For this reason, it
can be used as a proxy indicator for
sounds such as voices;
• Green space data (grass and tree
coverage) as indicators that might
aect noise level distribution due to
dierent properties in absorption,
diusion or scattering.
The measurement results show that
Rivierenhof Park has the highest noise
levels adjacent to the busy highways with
LEq between 60 and 75 dBA. Addition-
ally, the background noise level (L90) is
between 60 and 75 dBA. It can be seen
that the sharpness indicator in the park
in Figure 2 has highest values at the
centre as well as in areas where people
would be the more dominant sound
source compared to road trac noise.
Figure 1 - Noise map of
Rivierenhof Park (LAeq,1s)
Figure 2 – The yellow-
to-purple coloured dots rep-
resent the 1-minute moving
average of the indicator
of high frequency content
(S50,1min)
Applied urban sound planning 75

In order to evaluate the subjective re-
sponse to the sound environment, the
public was asked to complete a ques-
tionnaire including 13 statements to
analyse the inuence of the park, the
meaning of tranquillity and the heard
(attended) types of sounds and the rel-
ative membership. All of their responses
were assigned to the calculated tranquil-
lity viewpoint group with a relative mem-
bership (social relationships, sounds and
nature, and silence). The questions relate
the sounds that the park visitors repor-
ted to have heard during their visit to the
park and the degree of membership of
the three viewpoints on tranquility.
As can be seen in Figure 3, the par-
ticipants who heard a large number of
natural sounds do generally not belong
to the groups associating tranquillity to
natural sound sources or to silence. On
the other hand, in the group of partici-
pants belonging to the same tranquillity
belief groups, a pronounced increase
is found in the hearing of mechanical
sounds. Correspondingly, it can be
argued that the mechanical sounds
(often characterized as unwanted) are
noticed more by those people associ-
ating tranquillity to silence and natural
Figure 3 – Appreciation of sounds in parks
Urban sound planning - the SONORUS project
76
Figure 4 – Average values of L90 and relative
condence intervals depicted for each green
space category in Rivierenhof Park

sound sources. Therefore, such people
hear these antagonizing sounds more
than the sounds that they actually want
and expect to hear in a tranquil environ-
ment.
Rivierenhof Park is also the objec-
tive of study for the interaction of green
space parameters and sound levels. In
this case there is a negative correlation
between the tree coverage and the
average levels of L10 and L90, suggest-
ing that an increase in the amount of
trees within the parks can provide fur-
ther noise level attenuation (Figure 4). A
second outcome is that the noise levels
within the “tree coverage” are lower than
the noise levels in the “grass coverage”.
To continue with the application of
urban sound planning, the study conti-
nued with the development of a model
for human perception of environmental
sounds and its translation to an articial
Figure 5 – Articial sound attention model output for Rivierenhof Park
Applied urban sound planning 77

sound perception model (see Figure 5).
The current status of technology allows
a monitoring of cities with a high spa-
tial resolution. However, the challenge
starts within a soundscape approach that
analyses the person-environment inter-
action, i.e. the perception. The inclusion
of such translation will strongly help in
the understanding and assessment of
urban sound environments. Although
the models will not be described in detail
(for more information, check the “Urban
soundscape” Chapter), it is worth to
mention that they describe and imple-
ment two basic listening styles: the rst
characterizes the holistic background lis-
tening experience and the second imple-
ments the analytic listening considering
the person’s attention and the noticed
sounds
The model is expected to give statis-
tical information about individual per-
ception. For example, mechanical sounds
were almost constantly noticed next to
the busy roads. Human sounds appear
mostly in the centre area of the park.
Natural sounds were often noticed in
the north area of the park. However, the
model also includes an important por-
tion of human sounds activation in areas
without many people during the mea-
surement campaign. As a consequence
of the implementation of attention
processes, the model allows not listening
attentively to either of the sounds, as a
human park visitor would do.
To complement this study applying
an urban sound planning approach, the
study goes beyond the analysis of the
distribution of dierent activities within
the park, with the aim to make it more
attractive to the users. The proximity of
dierent paths, the accessibility of the
park and dierent activities have been
studied, as well as the quality of inte-
gration in the city. It was concluded that
the southern part of the park has more
chances to be visited than the northern
part due to the presence of water (lakes)
and the activities around it. Improving
accessibility, creating new paths, and en-
hancing the lake as the nal destination
could result in more visitors for these
areas.
Controlling the urban sound en-
vironment: improvement of road
layout
Rivierenhof Park is divided by a 1 km
road with two trac lanes, each with an
adjacent bicycle and pedestrian path.
The current urban layout decreases
pedestrian safety and interrupts the co-
hesion of the park as only four crossing
points are available. At the same time,
the linear geometry of the road en-
hances vehicle acceleration. From the
aesthetic and visual point of view, it gives
Urban sound planning - the SONORUS project
78

the misleading impression to the visitor
that this is the end of the park. Addition-
ally, this road is a signicant source of
road trac noise, with LEq values around
70 dBA.
In this regard, the working group
proposed the following solutions to
mitigate the problems generated by road
trac, reducing road trac noise emis-
sion and increasing pedestrian safety and
urban green space quality:
• Separating the two trac lanes;
• Reducing the number of lanes: redis-
tribution of the trac ow to other
possible routes;
• Reducing trac speed with calming
measures, such as the inclusion of
chicanes along the road, known to
reduce trac speed. This measure will
also avoid the linear perception of
the road, giving visual continuity to
the park;
Figure 6 – Scenarios modelled: current scenario, scenario 1, scenario 2
Applied urban sound planning 79

• Adding a porous road surface mater-
ial, reducing noise emission;
• Locating vegetated low barriers next
to the source (see “Controlling the
urban sound environment” Chapter);
• Including absorbent vegetated areas
between source and receiver, reduc-
ing noise levels at the pedestrian
paths while giving visual continuity to
the park;
• Locating pedestrian paths and bike
lanes at a further distance from the
road.
Most of the proposed solutions were
acoustically calculated using a wave
model (a Finite-Dierence Time-Domain
method, FDTD) (to know more, see the
Chapter on “Prediction and auralisation
of urban sound environments”). The ad-
dition of dierent shapes of low barriers
was also assessed (see the “Controlling
the urban sound environment” Chapter).
The dierent noise abatement meas-
ures are included in two new scenarios:
scenario 1 (Sc1) keeping the two-lane
road, and scenario 2 (Sc2) modelling a
one-lane road (see Figure 6). Both scen-
arios are compared to the current situa-
Figure 7 – Noise exposure
along the cross section at 1.5
m height. (a) Scenario 1,
(b) Scenario 2
Urban sound planning - the SONORUS project
(a)
(b)
80

tion, where both the cyclist and pedes-
trian paths are located next to the road.
Seven dierent cases are calculated,
including the current scenario, the two
future scenarios without barriers and
the future scenarios with the two barrier
types (see Figure 6). In both proposed
scenarios, pedestrian and cycling path
are located at a further distance from the
road (8.5 and 17 m respectively), making
it possible to include two absorbing
green areas.
Two dierent low barrier types
(vertical or 30 degrees inclined) of 1.1 m
height have been assessed taking into
account dierent trac speeds (50, 40
and 30 km/h). Both barrier types are
modelled with absorbing vegetation
on the top and receiver sides. The total
sound pressure level distribution along
the section at 1.5 m height in the dier-
ent cases are compared to the current
situation (see Figure 7). The inclined
low barrier for scenario Sc2 is the most
eective solution, with a reduction of 11.5
dBA in the exposure for the same posi-
tion. The comparison between the two
charts shows the importance of limiting
the trac speed achieving around 5 dBA
reduction. It should be noted that the
modelling results have been performed
in two dimensions, assuming no variation
along the third dimension. They corre-
spond approximately to a 3D model from
the section innitely extruded, which is
not a real-life case. However, they are
useful for comparing the eciency of
each noise abatement.
The exposure reduction in dBA rela-
tive to the reference values in the current
case (cyclist at 4 m and the pedestrian
at 5 m) is displayed (see Figure 8). Here,
large noise reductions are shown, es-
pecially in the cases with the inclined
low barrier, where a 25 dBA reduction is
achieved on the cyclist exposure at 8.5
m distance and 30 dBA reduction for the
pedestrian exposure at 17 m in scenario
Sc2.
Attenuation (dBA)
Figure 8 – Noise reduction
(dBA) for cyclist at 8.5m and
pedestrian at 17 m from the
road centre in both scen-
arios. Vegetated substrate is
considered
Applied urban sound planning 81

From this analysis the main conclusions
are that:
• The combination of dierent noise
abatement measures proposed, in-
cluding distance increase, can reduce
up to 25 dBA for cyclists and up to 30
dBA for pedestrians;
• The suppression of one trac lane
gives an overall reduction of around
3 dBA;
• Decreasing the speed from 50 to 40
km/h reduces an overall noise level
by around 3 dBA. Reducing the speed
from 40 km/h to 30 km/h additionally
reduces noise by around 3 dBA;
• Displacing the cyclist and pedestrian
lanes further away from the source
achieves a reduction of around 7 dBA
and 17 dBA respectively.
• Vegetated ground surfaces only
reduce noise at far distances. Reduc-
tion of around 6.5 dBA is achieved for
pedestrians at 17 m from the road.
• The addition of a low vertical barrier
reduces noise by around 6 dBA for
cyclists, but practically no eect is
found for pedestrians.
• The inclined barrier achieves bigger
reductions than the vertical one in all
cases. It additionally reduces noise
by around 4 dBA in Sc1 and around
2 dBA in Sc2 for cyclists. For pedes-
trians, a reduction of nearly 5 dBA is
achieved in Sc1 and 3 dBA in Sc2.
Virtual Reality as a tool to
combine visualisation and
auralisation
The Virtual Reality technology is an inter-
esting tool to combine visualisation and
auralisation, allowing a comprehensive
analysis of the urban environment during
the design phase. Additionally, it is an
eective means to communicate propos-
als to stakeholders as they can be virtu-
ally transported to the newly designed
urban area.
Virtual Reality was applied in
SONORUS to improve the urban sound
environment, assessing dierent reno-
vation designs for the Turnhoutsebaan
bridge, which passes over a busy High-
way in Antwerp and is the only access
to Rivierenhof Park from the city centre.
Despite the spatial proximity, the con-
junction of roads and railways constitutes
a real obstacle to reach the park. Walk-
ing on this bridge is currently extremely
noisy and gives a feeling of insecurity.
A test was performed with normal
hearing participants experiencing a walk
over dierent virtual environments on
the bridge using the Oculus Rift (see
Figure 9). Dierent urban arrangements
were modelled and dierent noise abate-
ment measures (noise barriers) were
conveniently auralised.
It was shown that human percep-
tion of the urban environment is multi-
Urban sound planning - the SONORUS project
82

sensorial (especially, the visual sense is
related to the auditory sense) and such
interactions can have an important eect
on people’s noise perception. As an
example, the eect of the noise barriers
is not only a noise reduction at the ear
of the pedestrian. It also partially hides
the sound source from sight, and the
visual design of the barrier may help to
improve the overall perception of the
environment.
This demonstrates that noise control
in the context of soundscape design
should not only consider reducing levels
of unwanted sounds, but also improve
the audio-visual perception of the urban
environment. Consequently, architects
and urbanists play an important role in
the perception of the urban environment
and the participation of an urban sound
planner is recommended as an integral
part of future urban planning.
Figure 9. Virtual reality applied to improve the urban sound environ-
ment at Turnhoutsebaan bridge
Applied urban sound planning 83

Map of
Gothenburg
(Frihamnen
area marked in
red)
Götaälv bridge
to the northeast
of the area
One pedestrian bridge links the
Frihamnen area with the north side. The
bridge goes over the highway and rail-
way that run along the northwest side of
the area.
Urban sound planning - the SONORUS project
84

GOTHENBURG, FRIHAMNEN
AREA
PLANNING GOAL: Recover and transform
a central area with residential purposes,
including a large city park.
MAIN RESEARCH TOPIC: Controlling the
sound environment through noise pre-
diction methods.
Mesoscale level
OUTPUT: Development of a tool to study
the impact of future road trac scen-
arios on the sound environment through
microscopic trac alternatives based on
real situations.
Description
The city of Gothenburg is located at the
mouth of the river Göta in west Sweden.
It is the second largest city in Sweden,
with 550 000 inhabitants in the urban
area.
The study area of the SONORUS
project is Frihamnen (Freeport). It was
built in the 1920s as the most inner har-
bour located in front of the city centre.
The freeport was closed in 1996. Since
then, this area of around 100 ha (the
same size as the city centre) has been
enduring a severe transformation.
The area presents a unique opportunity
to improve and test new ideas within the
urbanization process. This unique occa-
sion is presented by the city in the way
of a long-term project to be nished by
2040, transforming it into a dense-mixed
area with around 15 000 people and the
same number of working places.
However, Frihamnen is a challenge
from the environmental point of view,
where the list of aspects contain rising
water levels, contaminated soil and wa-
ter, and air and noise pollution coupled
with the infrastructure problems.
Frihamnen within SONORUS
SONORUS working group got the task to
analyse the acoustic situation and under-
stand the impact of future developments
on the sound environment from a holis-
tic perspective. In this regard, Frihamnen
presents a great potential to become
a pleasant area. However, the project
needs to look at a long-term perspective
under a holistic approach, where retrot-
ting might be avoided due to the in-
crease in costs and technical complexity.
Frihamnen is a project largely driven by
the need of densication. Moreover, the
complexity is increased by the interest
it has generated among the city oces,
the citizens and the building companies
around it.
Our concern is on how to obtain
a good sound environment, attending
to the above described interactions. To
exploit all potential benets of obtain-
ing a good sound environment, guide-
line values may be a rst approach, but
certainly not the nal answer within an
Applied urban sound planning 85

urban sound planning approach.
To get a glimpse of the current noise
situation, a noise map reecting the day-
evening-night equivalent level (Lden)
is already assessing the problematic
environment (see Figure 10). The whole
area is submitted to levels above 65 dB,
calculated according to the Swedish
standard. The World Health Organization
(WHO) stated in the Good practice guide
on noise, that Lden values around 50 dB
would represent a good sound quality in
a residential area. The Swedish legislation
considers the LAEq,24h limit to be 55 dB.
However, this limit level is raised in the
case the noise levels at the quiet side are
below 55 dB, in at least half of the living
rooms and bedrooms.
The main noise source in Frihamnen
is the road trac. Nevertheless, a high
contribution is also coming from the
trains traveling northwest-northeast.
However, as we stated in the previ-
ous Chapters (see “Controlling the
Figure 10 – Noise map of Frihamnen area. Day-evening-
night noise levels
Urban sound planning - the SONORUS project
86

urban sound environment” Chapter),
these type of maps, which are mainly
based on static trac situations, are not
adding enough information about how
the sound power of sources is varying
along the roads and over time, where
vehicles are constantly braking and
accelerating. Such noise maps are not
giving enough information about how to
improve the area embracing a view that
places sound quality on the urban plan-
ning agenda.
Transport management and trac
design are decisive if one wants to start
talking about qualities in the sound
environment. To study these types of
projects, the assessment includes a
macroscale perspective, focusing on how
the city works. The building and trans-
portation structures comprise a cascade
eect within the rest of the urban scales.
Infrastructures such as the train line and
highways are aecting the overall sound
environment (to know more on this type
of scales and the implications it has on
the sound environment, read the intro-
duction of the Chapter on “Controlling
the urban sound environment”). This
type of scale is tackled from a long-
term perspective, looking at all agents
involved. In the study of Frihamnen, the
focus is on looking toward the next scale
aected by this macroscale planning
design, i.e. the mesoscale, capable to
give enough answers to improve the
sound environment of large areas.
Within the mesoscale, the appropri-
ateness of the sound environment to the
desired planned activities and functions
in the area is one of the main ideas to
explore. However, certain proper condi-
tions are needed. In an area dominated
by high exposure to noise, the spatial
functions and uses that this part of the
city could oer to its inhabitants is prac-
tically none. With such high exposure to
noise, the idea to, for example, sit in a
park to read a book not being disturbed
by trac noise or rest at home without
noticing the high noise levels coming
from the road trac all the time, etc., will
be extremely dicult to realise, unless a
careful plan of the sound environment is
included in the decision-making process.
If this is not addressed at the planning
stage, it is very likely that in order to mit-
igate the noise and increase the sound
quality of the area, the resulting design
will end up being a patchwork design,
e.g. with noise proof windows, standard
noise barriers and suboptimal use of
spaces due to their high exposure to
noise. This will also have enormous long-
term consequences on complexity and
costs. The SONORUS vision tries to avoid
this retrotting state, where everything
becomes complex and expensive.
The city is making a large eort by
Applied urban sound planning 87

creating several workshops and activities
about the area. However, acoustic
aspects are generally not present in
those activities. As part of the Urban
Sound Planning approach, SONORUS
organised a workshop with members of
the city’s Planning Oce and Environ-
mental Oce (see section “Urban Sound
Planning workshop”).
As mentioned previously, the trans-
port management and trac design is
key if one wants to start talking about
qualities in the sound environment. For
this purpose we started to study the
trac scenario proposed by the Trac
Oce (this model has been modied in
the latest project reviews).
In general, noise mapping software
work with static trac, which may lead to
underestimations. Therefore, a dynamic
assessment tool, representing the kine-
matics of the vehicle is developed within
the SONORUS project. The purpose is
to study those plausible strategies that
could improve the sound environment of
the area. These strategies seek to ad-
dress the appropriateness of the sound
environment to the place (closeness to
water, the location of residential areas,
the inuence of major infrastructures,
etc.).
Urban Sound Planning in praxis:
trac strategies, noise emission
tool and results in Frihamnen
area, Gothenburg
The tool is understood as a dynamic
assessment composed by microscopic
trac simulations including the vehic-
les’ kinematics, which are computed to
obtain single-vehicle noise emission (see
the Chapters on “Controlling the urban
sound environment” and “Prediction and
auralisation of urban sound environ-
ments”).
The study focuses on nine alterna-
tive trac strategies. Five of the strate-
gies are related to speed reductions or
acceleration eects based on the rst
scenario (the one proposed by the Trac
Oce). The rest of scenarios present
dierent layout transformations (see Fig-
ure 11). The models are made to assess
the worst trac demand situation (peak
hour). The requisite is that all scenarios
have to allocate the same trac, for
example, the same number of vehicles
traveling from one point should be able
to reach their destination in all scenarios
We selected 11 receiver points dis-
tributed among the area to see how the
acoustic properties are changing among
them (see gure 12, scenario 1). The
sound power level of all individual vehic-
les during the peak hour is estimated.
The inuence of vehicle dynamics is
Urban sound planning - the SONORUS project
88

Figure 11 – Studied scenarios
already shown in scenario 9 in Figure 12,
(acceleration noise omitted) in compari-
son with base scenario (1), with die-
rences around 1-3 dBA for the selected
receivers. Also, scenario 8, without heavy
vehicles, is giving dierences in terms of
equivalent sound pressure level (1-2.5
dBA).
With this type of tool is also possible
to see the contribution to the equivalent
sound pressure level, for e.g. 15 minutes
(LAeq,900s), from each road segment to
a certain study point (e.g. receiver), cre-
ating a kind of contribution noise map.
The same way, the largest LAeq,1s value
during the period, here denoted Lpeak,
is analysed. (See Figure 13, top, for equ-
ivalent as well as peak levels.) To study
data through maps, roads are grouped
into segments (here ca 150 segments in
total).
In general, when assessing LAeq,1h
the most favourable scenarios are 3, 5, 8
and 9. Speed reduction in the highway
(scenario 5) might be a good solution to
reduce noise levels in the majority of the
study points. Keeping only light vehicles
(scenario 8) reduces levels up to 2.5 dBA.
A study on time patterns should be
made to give further information about
the test site opportunities (to see more
about time patterns and number of
Applied urban sound planning 89

Figure 12 – Dynamic noise maps for the second simulated quarter hour
reect the equivalent sound pressure level for the second quarter hour
(LAeq,900s)
Urban sound planning - the SONORUS project
90

Figure 13 – LAEq,900s
contribution per link
and sound pressure
level
Applied urban sound planning 91

events go to the Chapter on “Controlling
the urban sound environment”).
From this work, we have concluded
that there is a need to confront the pro-
ject under a multi-perspective scenario,
letting the urban planning process meet
the requirements of the city, while oer-
ing concrete proposals from a holistic
point of view. The SONORUS working
group has been developing the research
in parallel to the development of the
project. Our aim has been to show dier-
ent alternatives that can be considered
by the city, but also to develop a tool
that might be used as part of the design
process in other urban developments.
Some recommendations proposed
are looking toward:
• The reinterpretation of the transport
system: controlling the sound envir-
onment through transport manage-
ment and trac design strategies
focusing both on a macro and micro-
scopic trac study;
• Interest on time patterns with a large
impact on nuisance: study through
dynamic trac situations;
• Rethink the opportunities to improve
the sound environment through the
study of the activities and functions
that each particular site is deman-
ding;
• Avoid complex and expensive solu-
tions through the application of the
urban sound planning approach as
part of the decision-making design
stage.
Urban sound planning - the SONORUS project
92

BRIGHTON, VALLEY GARDENS
PLANNING GOAL: Regain a park area for
pedestrians.
MAIN RESEARCH TOPIC: Soundscape of
urban parks including urban sound envir-
onment control.
Microscale level
OUTPUT: Characterization of the sound
environment by integrating a detailed
traditional noise mapping and sound-
scape maps through the perception
evaluation of the sonic environment
appropriateness. First assessments show
that this integration may be an eec-
tive methodology in the analysis stage,
supporting city planners with adequate
information and strategies to plan future
urban interventions.
Description
Brighton & Hove is a city of 250 000
residents and is one of the main seaside
destinations in the UK, both for national
and foreigner tourists. It receives around
400 000 visitors per year. Brighton &
Hove city has a wide range of restaurants
and cafes, and oers a varied nightlife,
which, along with the numerous art and
cultural events have created a thriving
city.
The drawback of being such a vi-
brant city is the added pressure in terms
of road trac and human activities re-
sulting in excessive noise and annoyance
therefrom.
The Valley Gardens site within
SONORUS
The Valley Gardens site is a green area
located in the city centre, which stretches
from the seafront roundabout (Brighton
Pier) to approximately 1.5 km into the
city.
The area constitutes a relevant
access for entering and leaving the city
and for accessing the seaside. Conse-
quently, it is largely aected by the high
noise levels from road trac. The resi-
dents do not use the green areas along
the site for their leisure activities.
Added to the problem of noise,
there are also mobility issues: some road
sections have a total of four lanes, nar-
row sidewalks and almost non-existing
cycling lanes which make it dicult for
people to move around.
In order to solve these problems, the
city of Brighton & Hove started a project
with the purpose of improving the area
and transform it into a safe and exi-
ble place that will attract residents and
visitors. This way, the area will become a
meeting place, connecting the city e-
ciently and safely however people travel.
The Valley Gardens project’s aim is to
upgrade the public spaces and improve
routes for pedestrians, cyclists, drivers
Applied urban sound planning 93

Map of Brighton
(Valley Gardens
marked in blue)
View of the Royal Pavillion
A narrow strip
of the park
surrounded by
trac
Urban sound planning - the SONORUS project
94
1
2
3
4
5
6
7
8

and public transport. This project seeks
to minimise intrusive/unwanted noise
whilst at the same time introduce posi-
tive sounds. According to the city part-
ner, the intention for this site is to use
sound as a valuable resource rather than
a “waste product of poorly designed
areas”.
Nevertheless, the current situation
is deeply aected by noise problems.
The entire Valley Gardens area is being
exposed to high noise levels (Lden≥65
dBA and Ln≥60 dBA), which are above
the recommended levels by the WHO.
One of the rst challenges proposed by
the city to the SONORUS working group
was to tackle this problem in a holistic
way, improving the soundscape of the
park area.
Urban Sound Planning in praxis:
soundscape design strategies
and results in the Valley Gardens,
Brighton
In order to have a solid background for
future proposal and design, it was es-
sential to have a good acoustic charac-
terisation of the current Valley Gardens
situation. Thus, two main strategies were
dened: producing a more detailed road
trac noise map of the Valley Gardens
area characterizing the sound environ-
ment both from the acoustic metrics and
the individual perceptions point of view.
The noise map for the day-time level (Ld)
was generated based on fty-ve select-
ed receiver points, calculated according
to the CRTN method (used in the UK).
A noise survey and a soundwalk
campaign were carried out at eight
selected locations close to and within
the Valley Gardens; (1) Seafront, (2) The
Old Steine, (3) Royal Pavilion, (4) Victoria
Gardens South–Victoria Statue, (5)
Victoria Gardens South–Mazda Fountain,
(6) Victoria Gardens North, (7) St Peter’s
Church and (8) The Level.
For each location, 21 participants
were asked to listen to the sound envir-
onment for 2 minutes and ll in a struc-
tured questionnaire. The questionnaire
included questions about: participant’s
demographic information, expected
social or recreational activities, notice-
ability of dierent sound source types,
semantic scales of perceptual attributes
related to the sound environment, and
overall quality and appropriateness of
the sound environment. Two sets of
questions on a ten-point scale were fur-
ther considered to assess:
• Soundscape quality: two questions
considered the perception of the
sound environment, ranging from
“very bad” (0) to “very good” (10),
and the appropriateness of the sound
environment, ranging from “not at all
appropriate” (0) to “completely ap-
propriate” (10).
Applied urban sound planning 95

• Sound source proles, to evaluate to
what extent dierent urban sound
sources were present: trac noise,
other urban noise sources (sirens,
construction noise, etc.), sounds of
individuals or natural sounds. The
scale ranged from “do not hear at all”
(0) to “dominates completely” (10).
The results (see Figure 14) show that only
two of the selected locations had high
scores both on the overall sound envir-
onment quality and appropriateness of
the sounds environment to the place:
The Royal Pavilion and The Level. This is
likely due to the fact that those are the
only two sites that are not directly
exposed to road trac noise, which has
been found to be the main cause of
noise annoyance in the investigated area.
A “sound sources dominance map”
was also produced by implementing the
mean individual scores for the sound
source proles question into a Geo-
graphical Information System (GIS) plat-
form, generating a prediction surface for
the study area, using the Kriging inter-
polation method (Figure 15).
The results show that road trac
noise sources dominate the area and
that “sounds of individuals” had low
scores, which suggests the absence of
perceived sounds from human activities
throughout the park.
A combination of noise mitigation
actions and dierent soundscape
Figure 14 – Median
individual responses for
appropriateness of the
sound environment to
the place and overall
sound environment
quality
Urban sound planning - the SONORUS project
96

strategies has been proposed in order
to assess potential benets of an overall
solution aimed at improving the Valley
Gardens sound environment. For this, 15
study points were selected (see Figure 16
and Table 1).
Dierent noise mitigation actions
were proposed and discussed with the
city planners. The most eective ones for
the majority of the study points are the
banning of heavy vehicles and the intro-
duction of a continuous absorbing noise
barrier around the park. However, the
noise barrier solution will need a fur-
ther study in order to be adapted to the
several particularities of the urban layout,
such as crossings, bike lanes, etc.
Figure 15 – Sound
source dominance
map:
Trac (a),
Other urban sounds
(construction, sirens,
etc) (b),
Sounds of indi-
viduals (c),
Natural sounds (d)
Applied urban sound planning 97

Table 1 - Noise mitigation actions
Case Description
1No reections from buildings
2Speed limit set to 20 km/h
3Continuous absorbing noise barrier (1 m. height)
around the park
4No heavy vehicles
5Buses on the West bound and remaining trac on
the East bound
6All trac to the East bound
-14
-12
-10
-08
-06
-04
-02
00
02
04
P1 P2 P3 P4 P5 P6 P7 P8 P9 B1 B2 B3 B4 B5 B6
1
2
3
4
5
6
Cases
Figure 16 – Noise mitigation actions (Attenuation in dBA)
Urban sound planning - the SONORUS project
98

In an attempt to improve the urban
sound environment, soundscape
strategies may be used in the case noise
reduction measures were not feasible.
However, for noisy environments, it
is strongly recommended to reduce
noise levels previous to the inclusion of
soundscape measures. For the present
study, the proposed soundscape strategy
aimed to achieve attentional auditory
masking for hot spots (suitable places
to improve the sound environment due
to its relevance and its high noise ex-
posure). The sound-pressure level of a
sound from walking on a platform
covered with gravel was compared with a
15-second excerpt of trac noise recor-
ded at a crossroads in Valley Gardens.
A simulation of the comparison between
the walking sound on gravel and a typ-
ical background noise recorded on site
during the soundwalk is shown on the
next page. Figure 17 shows that the level
of the walking sounds has the potential
to exceed that of a typical road trac
noise as recorded on site. Therefore, it
seems reasonable to assume that this
solution could provide energetic as well
as attentional masking for the unwanted
sound source.
Data collection at the test site (both
objective measurements and individual
responses) conrmed that road trac
noise is the most relevant noise source
while being perceived as inappropriate
to the Valley Gardens area.
In summary, the traditional approach
provided by the road trac noise map
was extended by including results of
research featuring the overall sound
environment characterisation, in both
acoustical and perceptual levels, and
showed that the sound environment of
the site is not adequate to the visitors’
expectations. Together, the three tools
implemented by the working group
(noise maps, sound maps and sound-
scape maps) proved to constitute an
eective methodology at the analysis
stage, as well as for the planning of the
future site. The methodology supported
the city planners with adequate informa-
tion to plan urban interventions toward
an improved urban solution.
The main acoustic goal was to pro-
mote sound environments that can foster
health and wellbeing for citizens. In order
to implement the holistic concept, the is-
sues related to the sound environment of
the test site were approached from both
a conventional noise control perspective
and a soundscape perspective.
Applied urban sound planning 99

Urban sound planning - the SONORUS project
100
Walking sound
on grave
Background noise
(Leq = 65 dB)
Time (s)
SPL
(dBA)
Figure 17 – Results of masking eects of proposed solution
l

ROME, THE COLOSSEUM,
PALATINE AND ROMAN FORUM
AREA
PLANNING GOAL: Improve the perceived
quality of an archaeological area for
visitors.
MAIN RESEARCH TOPIC: Controlling the
urban sound environment through noise
mitigation actions and soundscape with-
in an archaeological area.
Microscale level
OUTPUT: Integration of noise maps and
acoustic measurements with a percep-
tual analysis to characterise the current
situation. First assessments indicate that
poorer general judgements are related
to low ratings of soundscape quality.
Description
Rome is well known for its historical and
archaeological heritage, where the most
important monuments are the Colos-
seum and the Roman Forum area, with
6,5 million visitors in 2015. This situation
suggested the emergence of new strat-
egies to approach to heritage interpre-
tation, improving the liveability of the
space and the surroundings, while en-
hancing the experience and site’s iden-
tity. The site is immersed in the urban
structure with an area of around 40 ha.
Busy roads and high human activity are
surrounding the area.
The Colosseum, Palatine and
Roman Forum area within
SONORUS
In terms of its sound environment, the
area is considered a highly protected
environment where quietness is a basic
characteristic for its use. Despite all the
regulations, the sound environment is
not appropriate to the activities and uses
of the space. Road trac noise levels
above 65 dBA (LEq) are generally present
in the area. The municipality has taken
some actions to reduce the noise ex-
posure by banning private trac from
around the Colosseum in the Fori
Imperiali street. Due to this, around 1300
veh/h in the peak morning hour are
removed from the area. Moreover, con-
struction activities are currently present
in the surroundings of the area, to en-
able a new metro line.
The area confronts a wide range of
challenges in order to protect, under-
stand and value the archaeological area.
These challenges cover a broad perspec-
tive, including: the improvement of qual-
ity and attractiveness of outdoor spaces,
the need for protection of certain areas
whilst guaranteeing tourists’ access, and
integration in the city as a crucial part
of the cultural, societal and economical
development, promoting a participative
process including all interested stake-
holders.
Applied urban sound planning 101

Map of Rome
(Roman Forum,
Palatine and the
Colosseum
marked in
orange)
View of the
Colosseum and
pedestrian area
Via Celio Vibenna and Via di San
Gregorio passes to the east of the
Roman Forum, Palatine and the
Colosseum, exposing the areas to the
sounds from noisy mopeds and turist
buses
Urban sound planning - the SONORUS project
102

Applied urban sound planning
The SONORUS working group got the
task to evaluate the factors that can
aect the sound environment of the area.
In this area we nd a battleeld in which
the needs of residents and tourists are
largely confronted. Tourists’ and resi-
dents’ demands are evolving over time,
making it harder to state a unique inter-
vention. A multidisciplinary approach
requires both considering the problems
and enhancing the potential of the area.
In this study, the focus is mainly on the
tourist perspectives and expectations,
however, it has an eect that will help to
improve the overall quality of the area.
Urban Sound Planning in praxis:
soundscape and landscape
strategies and results: quality
perception in the Colosseum,
Palatine and Roman Forum area
The rst attempt is to analyse the sound
environment of the area and to study the
soundscape and landscape quality per-
ception. Four steps were taken, including
data acquisition, data analysis, conclu-
sions and proposals.
In the data acquisition stage, the
archaeological, cultural and historical
values are considered, including meas-
urements and survey campaigns made
at dierent periods throughout the year.
To get this type of data, a series of sound
measurements, eld surveys including
soundwalks, trac counts, trac record-
ings, and people density estimates were
included. In the survey campaign, the
questions involved sound and visual
aspects as landscape quality, soundscape
quality, overall analysis, etc. A 7-point
scale was used, rating them from 1 (very
bad) to 7 (excellent). All data collection
was made inside and outside the limits of
the Roman Forum and Palatine.
The results in Figure 18 conrm that
the area is visually very attractive for the
visitors. However, sound quality was not
rated in the same way. The study points
1, 2 and 3, located at the surroundings
of the Colosseum, present a low mean
score. In this area, controlling the sound
environment is extremely needed. The
main source at points 2 and 3 is road
trac, however, at point 1 people be-
come the main source, which may lead
to a dierent approach, trying to improve
the overall impression and attract their
attention to other qualities of the area.
It is also interesting to observe the
correlation between the lower general
judgements of the landscape quality with
low general judgements of soundscape
quality. However, this might be due to
other aspects inuencing the soundscape
appraisal, and needs further study.
Semantic dierential analysis was per-
formed using bipolar scales where dif-
ferent adjectives are able to characterize
the sound environment. These adjectives
103

Urban sound planning - the SONORUS project
Figure 18 – Soundscape
and landscape quality
perception inside and
outside the Roman
Forum and Palatine area
104

Applied urban sound planning
have been pointed out in several re-
search works: eventful, exciting, calm,
pleasant, chaotic, unpleasant, uneventful
and monotonous. (See Figure 19.) As a
result, the soundscapes of the areas 3
and 4 (intersection between Labicana
and Celio St., and the Palatine entrance)
are considered the more unpleasant
ones by more than the 60% of the inter-
viewees. On the contrary, the entrance to
the Roman Forum and the gardens near
Campidoglio Square are the more pleas-
ant ones. The Colosseum Square, the
Constantine Arch and the Garden nearby
the Campidoglio Square, although being
pedestrian areas, are considered chaotic
by approximately 45% of the inter-
viewees.
Considering the results related to
the unpleasantness of the sound envir-
onment, several measures should be
implemented based on a combination of
dierent approaches, looking rst to con-
trol the sound environment, i.e. reduce
noise levels, and then to integrate these
measures with soundscape design ap-
proaches. For that, prediction methods
and auralisation techniques might im-
prove the assessment and increase the
opportunities of the area. (See previous
Chapters to know more about dierent
tools that can be used.)
In summary, high noise exposure levels
are constraining the area and due to the
uniqueness of the place, the measures
need to go beyond the sound aspects,
looking to all characteristics involved in
the conservation and value of the area,
including the social, economical and cul-
tural values. The municipality of Rome is
very interested in improving the acoustic
quality of the archaeological area, but is
also conscious of the complexity of the
interventions due to the dierent author-
ities involved in the decision process of
this area.
Some recommendations proposed
to the municipality are looking towards:
• Reinterpretation of the perimeter of
the area, including strategies of urban
renewal aspects;
• Establishment of a monitoring system
in the area to acquire objective and
subjective data of the sound environ-
ment;
• Controlling the sound environment
through transport management and
trac design strategies;
• Provision of information to tourists
about the archaeological area, di-
recting their attention towards other
aspects such as information on the
set, observation of the landscape,
discovery through time, etc., rather
than towards the presence of disturb-
ing noise.
105

Urban sound planning - the SONORUS project
Figure 19 – Semantic
dierential analysis of the
eight areas under study.
The radial magnitudes
represent the percentages
of subjects that have given
a certain score on each
of the following 7 points
bipolar scales of the sonic
environment:
1=Unpleasant
7=Pleasant,
1=Uneventful
7=Eventful,
1=Monotonous
7=Exciting and
1=Chaotic
7=Calm.
Half of the neutral scores
(4) have been represented
in each positive or negat-
ive sector of the bipolar
scales.
106

In order to embrace an integrated ap-
proach to urban sound planning, every
test site organised a workshop with the
dierent stakeholders and city repres-
entatives. In practice, it is an opportunity
to exchange opinions and ideas among
those directly involved in the project,
for example, between the city’s planners
and working groups and the SONORUS
members. The intention is to acquire
knowledge about the project for an
attempt to provide solutions that may
improve the urban sound environment
with an integrated approach.
This type of study will increase
awareness among the people involved
in the urbanisation process as well as
among the citizens, which are constantly
Figure 20 – SONORUS Workshop Frihamnen
Urban sound planning
workshops - a tool to
improve interactive and
participative processes
Applied urban sound planning 107

demanding an improvement in the
environmental quality. These demands
require innovative solutions to cope
with the agents and systems involved in
urbanization processes. Although several
solutions to reduce the impact of noise
have been looking through a retrotting
perspective (increase of sound insulation
in buildings, noise barriers, etc.), the goal
of the SONORUS project is to avoid such
types of solutions. Our aim is to initiate
the urban sound planning study and its
practical implementation one step before
the urban decisions are made. This will
avoid expensive and complex solutions
and will further avoid overall physical
modications that could end in a retrot-
ting patchwork. To succeed in this holistic
methodology, a comprehensive ap-
proach and a continuous dialog between
the interested partners is needed.
The Urban Sound Planning work-
shop pointed at several challenges that
the areas are confronted with. Selected
steps in this methodology include the
study of the site, understanding its scale
and area of inuence, the incorporation
and comprehension of the several
urban systems involved in city planning
and their potential impact on the sound
environment, and the overall quality and
its perception. The study methodology
needs to go a step further by the con-
stant exchange of ideas with the dierent
actors involved in the project.
In this Chapter two workshops are
presented: the one realised at the Valley
Gardens site in Brighton & Hove and the
one at Frihamnen area in Gothenburg.
VALLEY GARDENS URBAN
SOUND PLANNING WORKSHOP,
BRIGHTON & HOVE
This workshop consisted of a project
update from the Valley Gardens project
manager, a site walk-about, and a sum-
mary of the current design proposals.
There was general agreement that the
background noise levels in Valley
Gardens test site need to be reduced by
at least 8 dBA before any enhancements
to soundscape experienced in the space
would be suciently benecial.
After the site walk-about, the partici-
pants (including the SONORUS network)
were split into three groups for a brain-
storming session. From the workshop,
a strategic approach (Table 2) was sug-
gested to condensate in two inter-related
key types of proposals for the test site:
controlling the urban sound environment
and providing positive soundscapes.
Urban sound planning - the SONORUS project
108

Table 2. Recommendations for dierent problems in the Valley Gardens, Brighton
Topic Problem Applying Urban Sound Planning:
recommendations
Controlling the urban
sound environment
Noise levels exceeding the
WHO guidelines
As the most dominant noise source was the road trac
noise, the recommendations of the workshop parti-
cipants focused on actions:
1. AT THE EMISSION:
• Low-noise road surfaces
• Limit the vehicles speed
• Promote awareness actions among the bus
• drivers
• Reduce heavy trac by goods distribution centres
2. AT THE PROPAGATION:
• Low vegetated barriers next to the roads
• Soil embankments surrounding the noise hotspots
of the park
• Encourage proled/textured building facade proles
rather than at reective surfaces
• Vegetated roofs or facades
• Moveable screens for music events
3. AT THE RECEIVER:
• Create acoustic ‘shadow’ areas at ground level using
physical barriers, level changes, topographic model-
ling within the park
• Creation of dierent areas according to users and
existing noise levels (e.g. sports activities, children
parks, resting areas etc.)
Provide positive
soundscapes
Perceived sound envir-
onment as bad and not
appropriate to the site
• Introduce ‘natural’ sounds through elements such
as wind in vegetative foliage or owing water
• Allow for ‘articial’ sounds via infrastructure such as
new lampposts
• Encourage bird song by adequate planting
• Encourage positive activity such as children’s play
Applied urban sound planning 109

Table 3. Recommendations for dierent problems in the Frihamnen area, Gothenburg
Topic Problem Applying Urban Sound Planning:
recommendations
Controlling the urban
sound environment
Time scale of the pro-
ject: construction will last
20-25 years. Impact on
visitors and residents.
High noise levels in the
entire area, both indoors
and outdoors with a large
number of sensitive areas
• Dierent kinds of noise maps able to reect the
construction process and its acoustic impact are
needed
• Build some kind of temporary acoustic screen
during the construction period
• Introduction of noise reduction treatments: noise
abatement in the propagation path through the
implementation of greener solutions
• Buildings and sound absorbing solutions: shift-
ing building positions between the two rows of
buildings next to the railroad could form a barrier
to the Jubilee park, located in the northern pier.
Incorporating vegetated roofs, especially in the
lower buildings, as well as green or sound-ab-
sorbing facades will increase the acoustic quality
throughout the area. Sensitive areas, such as
schools and hospitals, may, in case of maintaining
the current plan, require special noise abatement
treatments, including material aspects.
• Introduction of green and screening objects
through the use of low-height acoustic barriers
that could protect pedestrians and cyclists from
noise
FRIHAMNEN URBAN SOUND
PLANNING WORKSHOP,
GOTHENBURG
The workshop started with a visit to the
site by the working group. During the
second day, together with city represen-
tatives, a series of presentations about
the city, the area, the challenges, future
plans, environmental issues and current
sonic environment gave the opportun-
ity to the participants to get to know
more about the area. Afterwards, the
participants formed ve teams to work
on the situation and its possible solution
alternatives, mainly through sketches and
discussions, aided by maps and models
(see Figures 21 and 22). The outcomes of
the workshop are condensed into three
main topics: controlling the urban sound
environment, the acoustic quality and
the soundscape design, and the eco-
nomic aspects (Table 3). These topics are
concatenated and interpretations must
be made with this integrative approach.
Urban sound planning - the SONORUS project
110

Railway infrastructure: the
proximity to the railway
is already causing high
noise levels and vibrations
Road trac infrastructure,
transport management,
road design and con-
nectivity: avoid noise
abatement measures
in the future that will
become dicult and
expensive
1) Distributing trac
throughout the area will
result in a larger zone
with high noise levels
2) High noise levels
coming from the south
due to the bridge
• Reduction by screening is the primary eect, for
example through the construction of a sloped
roof/building, which could also be designed as a
pedestrian path. Presumably, this would facilitate
the crossing to the other side of the motorway, in
an attempt to erase the “urban scar” that this road
is drawing in the northern part of Frihamnen.
• Concentrating trac and applying preventive
solutions in surrounding limited areas will not only
reduce the costs, but also attend to the spatial
conguration, bringing acoustic quality as a re-
sponse to the functions and uses
• The road parallel to the motorway will have a
large impact in terms of noise levels at the three
piers. This road could be allowed for residents
with electric vehicles and electric buses only
• The introduction of an electric shuttle bus and the
promotion of cycling and walking routes could
improve the sound quality of the entire area. This
entails a careful study about the connectivity and
accessibility.
• To avoid high noise levels at the south part, the
new bridge requires a careful design, incorporat-
ing a good shielding through the use of screens.
Finally, the noise coming from the city centre
should be considered in the analysis of the sound
environment of the area.
Proposal for the
northern part of
Frihamnen
Applied urban sound planning 111

Acoustic quality and
soundscape design
The high noise levels will
constrain the popularity
of the area, especially
during the constuction
period
Accessibility and sound
attractiveness: access to
both the city centre and
the north area is one of
the key sets in this project
Park area and piers: to
cope with the uses and
functions of this area as
a park, special acoustic
qualities are needed. The
area will be submitted to
high noise levels during
the construction period,
which will be around 20
years.
• Promotion of the area among residents: ideas on
possible compensations, such as attractive activit-
ies that make the best out of the acoustic quality
• The passage through the area should be attractive
and accessible. For this, the city could use sound
to connect the space as a kind of heritage, reect-
ing the possibilities to keep and recall its past as a
former industrial area and harbour.
• Build a landmark/soundmark throughout the
piers. Taking advantage of the positive sounds
that water features may bring to Frihamnen, in-
corporating the waterfront history (e.g. sounds of
waves on resting boat hulls), oating bridges and
shipyard sculptures as a variation of the sound en-
vironment as well as dierent pavements capable
to reduce attention to road trac noise.
• The park activities could be oriented according to
the noise exposure of the area. Possible functions
might be a recreational park with a large number
of activities e.g. concerts, playground, sports, etc.
• Topography as an alley through the construction
of a railroad-oriented slope, incorporating the
attractive idea to Gothenburg citizens of a running
track in the park, which could block the noise from
the northern infrastructures
Economic aspects The impact of the low
attractiveness of the area
due to its high levels of
noise
• Careful study on the impact of future measures
intended to act only at a single city system. For
e x a m p l e , t h e t r a  c c a n b e p l a n n e d a s a d e t e r r e n t ,
providing a design dicult to drive through.
However, this approach might drive the area and
its surroundings to a higher noise exposure as
a consequence of the spread of trac and the
increase in the distance travelled.
Urban sound planning - the SONORUS project
112

Figure 21 – Working process and outcomes. Focus on controlling the urban
sound environment.
Figure 22 – Work-
ing process and
outcomes. Focus
on soundscape
design.
Applied urban sound planning 113

Within this project, the research made
has intended to start a process of in-
teraction with stakeholders through the
development of tools to minimize the
gap between urban planning practice
and current situations in cities.
From the beginning of the work
with the city partners, a holistic approach
has been intended, where the problem
and methodology is approached from
a broader perspective including the
concept of urbanisation processes as
a problem-solving method. The main
goal is to avoid unnecessary costs and
complexity where retrotting is avoided
as an option. However, the way is still
long and here we have just attempted to
take some steps toward the inclusion of
sound as a self-evident part of the urban
planning process.
Aligned to this, a SWOT analysis for
each test site was performed where the
strengths (S) relied on assessing the pro-
ject characteristics that give advantage
over others, the weaknesses (W) are the
aspects that place the project at a disad-
vantage relative to others, the opportun-
ities (O) are the elements that the project
could exploit to its advantage, and the
threats (T) are the ones that could cause
trouble to the development and success
of the project (Table 4).
One of the main concerns in the
working groups is the inability to see the
proposals realized. This has mainly to do
with the limited awareness that dier-
ent stakeholders and actors involved in
the current urban planning of our cities
might have related to the sound environ-
ment management.
Liveability of spaces has become
more relevant in recent decades, and
the role of urban sound planners and
their incorporation in the decision-mak-
ing process is extremely needed. In this
sense, the holistic urban sound plan-
ning approach shares its scope with the
urbanization processes to make spaces
more liveable while ecient, integrating
all systems and stakeholders in the pro-
cess and avoiding to tackle “noise issues”
as an independent entity.
The results presented in this Chapter
are intended to be an application of the
previous Chapters, showing that there is
a wide range of possible approaches to
a holistic planning that embraces sound
in the urban development agenda with
Implementing a holistic
approach in urban sound
planning
Urban sound planning - the SONORUS project
114

Test site
City
S W O T
Antwerp
Several professional
backgrounds in the
working group
Indirect contact with
the city planning
oce
Interventions made
previous to urban
decisions, observation
of consequences due
to the short-term
accomplishment
Sensitive areas related
to noise annoyance
with possible public
opinion and news me-
dia repercussions
Gothenburg
Freedom to imple-
ment innovative
urban sound plan-
ning proposals since
they are running
parallel with the city
project
Project complexity
and scale with a con-
siderable existing en-
vironmental deteri-
oration: sonic quality
is not in the current
planning agenda
Include the urban
sound environment in
the planning process
dening acoustic
capacities in order to
improve liveability
Inconsistency between
current project and
proposed vision: risk
of increasing environ-
mental degradation.
The group is not part
in the decision making
process
Brighton
Dierent professional
backgrounds in the
working group; direct
contact with the
city council project
manager and design
team
Sound is only a small
fragment of the over-
all picture; the time
scale of the research
project is dierent
to that of the design
scheme
Proposing local solu-
tion for critical issues
within the current
design
Recommendations
provided by urban
sound planners not
eventually considered
in the nal proposal
Rome
Indirect participation
within the rst phase
of the decision
making process
Acoustic interven-
tions are limited due
to the protective
legislation, despite
that high acoustic
standards are de-
ned for the site
Authorities are aware
of the noise problem
and are open to intro-
duce noise mitigation
actions to improve the
sonic quality of the
area
The group is not an
active part in the de-
cision making process
Table 4. SWOT analysis for the four areas of analysis
Applied urban sound planning 115

successful results.
For example, in Antwerp the urban
sound planning praxis intended to re-
store a damaged sound environment,
protecting pedestrians and cyclists.
Results from calculation methods have
shown that including adapted noise
abatement solutions in the propagation
path may result in large improvements to
the sound environment. Also, the study
goes beyond traditional ones through
the development of a model for human
perception of environmental sounds
and its translation to an articial sound
perception model, with very interest-
ing applications in the study of human
perception. Also the Valley Gardens site
in Brighton & Hove targets a damaged
sound environment. Outcomes in this
case show that the combined tool of
road trac noise maps, soundwalks and
“sound source dominance maps” may
enhance the possibilities to intervene in
the sound environment of an area on
a broader perspective. The Frihamnen
project in Gothenburg used a dierent
approach mainly due to its scale with a
large new urban development of great
importance due to its strategic location.
The tools used in the holistic approach
studied the sound environment from the
trac planning perspective. This dynamic
noise map tool is capable of analysing
trac time patterns and noise events,
rethinking the trac layout and study-
ing dierent possibilities to improve the
future sonic environment and its deman-
ded qualities. The Rome archaeological
area confronts a very particular situation,
where social, economical, and cultural
values are confronted. Moreover, tourist
and residential demands are leading to
dierent problem approaches. In order
to understand its particularities, sound
measurements and surveys have been
carried out and a series of recommenda-
tions for improving the sound environ-
ment of the area have been given.
Throughout the urban sound plan-
ning workshops, together with the tools
developed in the project, the SONORUS
working group attempts to facilitate the
process of understanding the importance
of incorporating acoustic quality aspects
in the designing process, as a self-
evident part of city planning.
Urban sound planning - the SONORUS project
116