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Research suggests that visual impressions of natural compared with urban environments facilitate recovery after psychological stress. To test whether auditory stimulation has similar effects, 40 subjects were exposed to sounds from nature or noisy environments after a stressful mental arithmetic task. Skin conductance level (SCL) was used to index sympathetic activation, and high frequency heart rate variability (HF HRV) was used to index parasympathetic activation. Although HF HRV showed no effects, SCL recovery tended to be faster during natural sound than noisy environments. These results suggest that nature sounds facilitate recovery from sympathetic activation after a psychological stressor.
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Int. J. Environ. Res. Public Health 2010, 7, 1036-1046; doi:10.3390/ijerph7031036
International Journal of
Environmental Research and
Public Health
ISSN 1660-4601
www.mdpi.com/journal/ijerph
Article
Stress Recovery during Exposure to Nature Sound and
Environmental Noise
Jesper J. Alvarsson *, Stefan Wiens and Mats E. Nilsson
Gösta Ekman Laboratory, Department of Psychology, Stockholm University, SE-106 91 Stockholm,
Sweden; E-Mails: sws@psychology.su.se (S.W.); mats.nilsson@psychology.su.se (M.E.N.)
* Author to whom correspondence should be addressed; E-Mail: jesper.alvarsson@psychology.su.se;
Tel.: +46-8-158-659; Fax: +46- 8-165-522.
Received: 26 January 2010; in revised form: 20 February 2010 / Accepted: 5 March 2010 /
Published: 11 March 2010
Abstract: Research suggests that visual impressions of natural compared with urban
environments facilitate recovery after psychological stress. To test whether auditory
stimulation has similar effects, 40 subjects were exposed to sounds from nature or noisy
environments after a stressful mental arithmetic task. Skin conductance level (SCL) was
used to index sympathetic activation, and high frequency heart rate variability (HF HRV)
was used to index parasympathetic activation. Although HF HRV showed no effects, SCL
recovery tended to be faster during natural sound than noisy environments. These results
suggest that nature sounds facilitate recovery from sympathetic activation after a
psychological stressor.
Keywords: soundscape; nature sounds; environmental noise; skin conductance level; heart
rate variability; stress recovery
Abbreviations: HF HRV = High frequency heart rate variability; SCL = Skin conductance
level
OPEN ACCESS
Int. J. Environ. Res. Public Health 2010, 7
1037
1. Introduction
In 1984, Ulrich demonstrated that patients whose windows faced a park recovered faster compared
with patients whose windows faced a brick wall [1]. Since then, several studies have demonstrated
restorative effects of natural compared with urban environments; these effects include increased
well-being, decreased negative affect and decreased physiological stress responses [2-7]. Ulrich [6]
suggested that natural environments have restorative effects by inducing positive emotional states,
decreased physiological activity and sustained attention. This agrees with Kaplan and Kaplan’s theory
that nature environments facilitate recovery of directed attention capacity and thereby reducing mental
fatigue [8], and with results showing that positive emotions improves physiological recovery after
stress [9].
Previous research in this area has mainly used visual stimuli, for example videos and photographs
of nature settings and urban areas [1,5,10]. However, sound stimulation is also known to be a potent
stressor, evoking unpleasant feelings (annoyance) and physiological stress reactions, especially at high
sound pressure levels [11,12]. Studies on the connection between sound environment and stress
recovery are currently lacking. Soundscape research has shown that natural sounds are typically
perceived as pleasant and technological noise as unpleasant components of the sound
environment [13-15]. It is therefore plausible that the sound environment may have a similar effect on
stress recovery as the visual environment.
Ulrich et al. [6] used video films with sound and found faster physiological stress recovery during
exposure to films depicting nature compared with urban environments. However, Ulrich et al. did not
control for sound pressure level. Indeed, the soundtrack to their films of urban environmental settings
had considerably higher sound pressure levels than the soundtrack to the films of nature environments.
This makes it difficult to determine whether the effect was related to the characteristics of the
environments or to differences in sound pressure levels. So, although positive effects of visual natural
environments are well established, no research has been done using only auditory stimulation with
controlled stimuli and sound pressure levels.
The autonomic nervous system controls various body functions: the sympathetic branch primarily
controls activation and mobilization, and the parasympathetic branch controls restoration and
relaxation [16]. Sympathetic activity can be indexed by skin conductance level (SCL) [17,18], and
parasympathetic activity can be indexed by the high frequency part of the power spectral density of
heart rate variability (HF HRV) [19,20].
Psychological stress can be elicited by factors such as failure to achieve and marital problems,
psychological stress also often has physiological consequences [21]. In the laboratory, psychological
stress is commonly induced by mental arithmetic and speeded Stroop tasks [22,23].
The purpose of the present study was to induce psychological stress and compare effects of different
sound conditions on the rate of physiological recovery. The sound conditions were chosen so that a
pleasant natural sound environment was compared with three less pleasant urban sound environments
dominated by noise. To study effects of sound pressure level on physiological recovery, the urban
sound conditions had higher, equal, or lower average sound pressure levels than the nature sound. Two
measures of physiological stress were used: SCL as an index of sympathetic activity and HF HRV as
an index of parasympathetic activity. Physiological recovery is associated with a decrease in
Int. J. Environ. Res. Public Health 2010, 7
1038
sympathetic activation (i.e., SCL decreases) and an increase in parasympathetic activation (i.e., HF
HRV increases). Because physiological stress recovery should be faster during exposure to pleasant
than to unpleasant sounds, we hypothesized that (a) SCL should decrease faster and (b) HF HRV
increase faster during pleasant nature sound than during less pleasant noise.
2. Methods
2.1. Participants
Forty university students participated in the experiment (24 women and 18 men, mean age = 27
years). All participants had hearing thresholds lower than 25 dB in their best ear, for all tested
frequencies (0.125, 0.5, 1, 2, 3, 4, and 6 kHz, Interacoustics Diagnostic Audiometer, model AD226).
The listeners received course credit for their participation. Electrocardiogram data were missing from
three participants (1 man, 2 women) due to electrode failure.
2.2. Experimental Design
The experiment consisted of three different parts: (1) One 5-min quiet baseline period, (2) five
2-min periods of testing (“stressor”), and (3) four 4-min periods of relaxation (“recovery”) during
exposure to one of four experimental sounds. Figure 1 illustrates the experiment schematically. Total
time for the experiment was approximately 35 minutes.
Figure 1. Experimental design with experiment duration on x-axis and expected stress
level on y-axis (S = stress test; R = recovery period for each experimental sound condition).
A 4 × 4 mixed design was used, with sound during relaxation as within subject variable and
presentation order of the four sounds as between subject variable (the sounds are described in detail
below). The participants were randomly assigned to one of four orders of experimental sounds, using a
Latin square matrix.
2.3. Stressor
The stressor was a two minute speeded mental arithmetic task (henceforth “the stress test”). The
task was to decide, within 3 s, whether a displayed equation was correct or false. The participants
answered by pressing one of two keys on a numeric keyboard. Their responses were evaluated as either
“correct”, “false” or “too late” (if later than 3 s). Feedback was presented on the screen (correct, false
Int. J. Environ. Res. Public Health 2010, 7
1039
or too late) and through earphones with a specific sound for each type of feedback. The equations
consisted of simple arithmetic operations, such as ‘543345 = 193’. The first two terms were integers
between 2 and 999, and the result of the equation was a positive integer below 1,000 which either was
correct or false (correct answer +/ 1–3). The operator could either be addition, subtraction, division or
multiplication. Each operator had 250 equations in a database, half correct and half false. Overall
performance (percent correct) was continuously updated and displayed to the participants in the upper
left corner of the screen.
2.4. Experimental Sounds
During each of the four recovery periods, participants were exposed to either a nature sound or a
noise. The sound pressure levels of the noises were higher, equal or lower than the sound pressure
level of the nature sound. The experimental sounds were selected from a large database of binaural
recordings of environmental sounds. The nature sound was chosen to be more pleasant than the three
noises, including the ambient noise of lower sound pressure level. The four experimental sounds are
described below.
(1) Nature sound. A mixture of sounds from a fountain and tweeting birds. The average sound
pressure level was set to 50 dB (LAeq,4min).
(2) High noise. Road traffic noise recorded close to a densely trafficked road. The average
sound pressure level was set to 80 dB (LAeq,4min).
(3) Low noise. The same noise as (2), but set to a lower average sound pressure level,
50 dB (LAeq,4min).
(4) Ambient noise. A recording from a quiet backyard, with a constant low level ambient noise,
mainly caused by ventilation systems of the buildings surrounding the yard. The average
sound pressure level was set to 40 dB (LAeq,4min).
2.5. Physiological Measures
For SCL measurement two electrodes were fitted by the experiment leader to the hypothenar
eminence of the non dominant hand. The SCL was measured as the conductance between the
two electrodes.
HRV measurements were derived from the electrocardiogram (ECG). Three electrodes were applied
by the participant themselves under supervision of the experimenter. The first electrode was positioned
five centimeters to the right of the middle of the upper sternum and the other two on the left and right
side of the stomach, just below the ribcage. HRV was calculated according to the procedure described
by Berntson and by Hejjel & Kelleny [24,25].
2.6. Procedure
Participants were informed that the goal of the experiment was to study physiological reactions
during a stressful task and that there would be sound presentations during the four minute pauses. The
participants were tested individually. They were first asked to wash their hands and were then seated in
a soundproof room, where they were given a written description of the experiment. After the
Int. J. Environ. Res. Public Health 2010, 7
1040
participants had given their consent to participate, electrodes were fitted to their bodies. They were
then asked to put on a pair of headphones and one trial version of the stress test was completed in order
to check the equipment.
During the baseline period, the participants were asked to relax in silence. At the end of the period a
prerecorded female voice reminded them that the first stress test was about to begin. After the stress
test, the female voice instructed the participants to relax and one of the four experimental sounds was
presented. This switch between stress test and recovery was repeated three more times (see Figure 1).
After the experiment, participants listened to the four experimental sounds one more time and
assessed the sound’s pleasantness, eventfulness, and familiarity on three bipolar category scales. These
attributes have been suggested as basic perceptual dimensions of sound environments [26]. Finally, the
participants’ thresholds of hearing were tested. Participants were informed only after the experiment
about the true purpose of the study (i.e., our interest in the sounds). The study was conducted in
accordance with regional ethical guidelines.
2.7. Equipment
The sounds were recorded with a binaural head and torso simulator Brüel & Kjær type 4100, with
two microphones type 4190 and two pre-amplifiers type 2669, one conditioning amplifier NEXUS
Brüel & Kjær type 2690 A 0S4 and a calibrator Brüel & Kjær type 4231 plus adapter model 0887. A
portable computer Dolch NPAC-Plus P111 with a 6-channel LynxTwo sound card stored the
recordings with 24 bit resolution and 48 kHz sampling frequency using Sound Forge 7. Editing and
mixing was performed in the same program. In the soundproof room, the signal was fed into a digital
filter and D/A-converter, Rane RPM 26z, and was then presented through Sennheiser HD 600
headphones. The whole listening system was calibrated using a pink-noise signal, measured at the
point of the listener’s ear. The frequency response of the whole listening system was flat within 2 dB,
1/3-octave-band levels, 2516,000 Hz.
The physiological data were recorded with a Biopac System MP100 at 1000 Hz. SCL was measured
with a Biopac GSR100C amplifier and EDA isotonic gel electrodes and ECG was measured with a
Biopac ECG100C amplifier and Red DotTM Ag/AgCl solid gel electrodes.
Both programming and presentation of the mental arithmetic stress task was conducted in
Matlab 6.5. The physiological data were analyzed in Matlab, while the HRV power density spectrum
(PDS) was computed in ACQ Knowledge 3.91. Statistical analyses were conducted in SPSS 16.
3. Results
3.1. Perceptual Assessment of Experimental Sounds
The perceptual assessment of the sounds showed that the nature sound was perceived as more
pleasant than the noises (Figure 2). This confirms that the selection of sounds was successful, as the
goal was to find a nature sound that was more pleasant than any of the noises. The low noise and the
ambient noise were similar in perceived pleasantness whereas the high noise sound was rated as the
least pleasant sound. The perceptual evaluation also showed that the high noise was perceived as more
eventful than the other sounds. The ambient noise was the least eventful and also the least familiar
Int. J. Environ. Res. Public Health 2010, 7
1041
sound, probably because it contained no distinct sound sources and therefore was perceived as an
undifferentiated background noise.
Figure 2. Mean values of perceptual attributes for the nature sound and the high, low and
ambient noises. Error bars represent the standard error of the mean.
3.2. Physiological Measures
Skin conductance level (SCL): The mean of successive 10 second periods were computed for the
recovery periods after each stress test. The mean of seconds 150–270 of the baseline period was used
as the baseline measure. Figure 3 shows baseline corrected SCL values over time, and Table 1 shows
descriptive statistics of these data.
Figure 3 suggests that although SCL immediately after the stressor was similar for the different
conditions, recovery was faster during exposure to the nature sound than to the three noise conditions.
The ambient and low noise had the second fastest, and high noise the slowest recovery. A slight
upswing during the last 50 seconds of the recovery period was seen for SCL recovery during the high
noise, possibly reflecting an increased arousal due to prolonged exposure to the unpleasant noise. In a
4 × 4 mixed ANCOVA, the mean SCL for each participant during the recovery period was used as the
dependent variable, sound as a within-subjects variable, and presentation order as a between-subjects
variable. The baseline measure was included in the analysis as covariate [27].
Figure 3. Baseline corrected skin conductance level (SCL) as a function of time, shown
separately for recovery during exposure to nature, high noise, low noise and ambient sound.
050 100 150 200 250
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
0.55
Time (s)
Skin conductance level (SCL)
Deviation from baseline (
S)
Nature sound
High noise
Low noise
Amb ie nt no is e
Nature sound
High noise
Low noise
Ambient noise
Int. J. Environ. Res. Public Health 2010, 7
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Table 1. The mean, median, max, min and standard deviation (SD) of participants
(n = 40) for SCL and HF HRV, baseline measures were computed from second 150–270,
recovery measures were computed over the whole recovery period.
Statistic (N = 40)
Period Sound Mean Median Max Min SD
Skin conductance level (SCL), µS
Baseline Silence 0.55 0.53 2.01 0.09 0.39
Recovery Nature 0.82 0.84 1.84 0.25 0.36
High Noise 0.87 0.90 1.49 0.25 0.35
Low noise 0.84 0.86 1.69 0.17 0.39
Ambient 0.85 0.84 1.80 0.28 0.38
High frequency heart rate variability (HF HRV), ms2/Hz
Baseline Silence 0.60 0.55 1.08 0.29 0.21
Recovery Nature 0.59 0.58 0.91 0.27 0.18
High Noise 0.60 0.57 1.01 0.31 0.20
Low noise 0.60 0.53 1.07 0.25 0.21
Ambient 0.61 0.57 1.04 0.32 0.19
The ANCOVA showed an interaction between presentation order and sound (F9,105 = 6.851,
p = 0.001). This effect reflected general SCL-increase during the experiment. The main effect of sound
was significant (F3,105 = 2.731, p = 0.048). Pairwise comparisons (t-tests) showed that mean SCL was
lower for Nature than High noise (p = 0.045); however, the differences between Nature and the other
two noise conditions did not reach significance (p > 0.05).
In an ANCOVA of sound (4) × time (24, the successive 10 second periods) with baseline as
covariate, the interaction between sound and time was significant (F69,2622 = 1.34, p = 0.034). This
finding suggests that recovery time for SCL differed among the sound conditions. As Figure 3 suggests
that polynomial trends (e.g., linear, quadratic) in an ANCOVA would not describe the recovery
functions well, a non-linear regression analysis was performed to obtain point estimates of recovery
time. To that end, we fitted an exponential function (Equation 1) to the mean SCL data shown in
Figure 3:
3
12
bx
y
bbe , (1)
where y is baseline corrected SCL, x is time (in seconds) and b1, b2 and b3 are constants. Figure 4
shows the fitted functions for the four experimental sounds. The fit, R2, for the nature sound, low noise
and ambient noise was > 0.99, it was slightly lower for the high noise, R2 = 0.96. RMS-error for the
nature, high noise, ambient and low noise sound was 0.0088, 0.017, 0.0090 and 0.0097 µS,
respectively. The half life recovery was calculated using Equation 1, by solving for x at the point
where SCL had been reduced by half, compared with its value at x = 0 (see dotted line in Figure 4).
The high noise had the longest half life of 159.8 s, the half life of the other three were 121.3 s for
ambient noise, low noise 111.4 s and nature sound 101.3 s. Reliable statistical testing of individual half
life values was not possible, since the estimated constants in several cases generated complex numbers,
that resulted in missing data when half life values were calculated.
Int. J. Environ. Res. Public Health 2010, 7
1043
Figure 4. Skin conductance level (SCL) as a function of time, shown separately for the
four sounds. Curves were fitted to the group data. Constants of Equation 1 and half life
value (x) are indicated in each diagram.
0.2
0.3
0.4
0.5
Nature sound
Skin conductance level (SCL)
Deviations from baseline (
S)
0.1626
0.3428
-0.1387
101.3
b1 =
b2 =
b3 =
x =
Half-life
High noise
0.2054
0.3071
-0.1185
159.8
b1 =
b2 =
b3 =
x =
Half -lif e
050 100 150 200 250
Ambien t n o ise
Time (s)
0.1607
0.3551
-0.1111
121.3
b1 =
b2 =
b3 =
x =
Half -lif e
050 100 150 200 250
0.2
0.3
0.4
0.5
Low noise
0.1822
0.3366
-0.1394
111.4
b1 =
b2 =
b3 =
x =
Half -lif e
Heart rate variability (HRV): We found no consistent effect of type of sound on HF HRV. Average
HRV values were not higher for nature sound than for the other sounds, and HF HRV for the high
noise was not substantially lower than for the other sounds. The HF HRV data for each participant and
recovery condition were tested in a 4x4 ANCOVA, with type of sound as within subject variable and
presentation order as between-subject variable. The baseline measure was included in the analysis as
covariate [27]. Neither type of sound, presentation order nor their interaction was statistically
significant (p > 0.05).
4. Discussion
The main purpose of this study was to test whether physiological stress recovery is faster during
exposure to pleasant nature sounds than to noise. Figure 3 suggests that mean SCL during the nature
sound was lower than for the noises. Although this difference was statistically significant only between
the nature sound and the high noise, detailed analyses of the recovery functions showed that half-life
SCL recovery was 937% faster during the nature sound than during the noises. These results suggest
a faster recovery of the sympathetic nervous system [16,17] during the nature sound. Because HF HRV
showed no effects of experimental sounds, this null finding suggests that the parasympathetic
activation may be less affected by sound during recovery.
The present results suggest that recovery from sympathetic arousal is affected by type of sound
(nature sound versus noise). Recovery was faster during the nature sound (50 dBA) compared with the
noises, including the low noise (50 dBA) and the ambient noise (40 dBA). The mechanisms behind the
faster recovery could be related to positive emotions (pleasantness), evoked by the nature sound as
suggested by previous research using non audio film stimuli [9]. Other perceptual attributes may also
influence recovery. The Ambient noise was perceived as less familiar than the other sounds (Figure 2),
presumably because it contained no identifiable sources. One may speculate that this lack of
Int. J. Environ. Res. Public Health 2010, 7
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information might have caused an increased mental activity and thereby an increased SCL, compared
with the nature sound (cf. [28]). An effect of sound pressure level can be seen in the difference
between high and low noise, this difference is in line with previous psychoacoustic research [12] and is
not a surprising considering the large difference (30 dBA) in sound pressure level.
The results from SCL are consistent with those of Ulrich et al. [6], who found a faster decrease in
SCL after audio-visual exposure to natural compared with urban environments. Ulrich et al. found a
similar effect on heart period. This disagrees with our HF HRV results. An explanation might be that
heart period is influenced by both sympathetic and parasympathetic activity [6], whereas our measure,
the HF part of the HRV, only is related to parasympathetic activity [17,19], the effects found on heart
period reflects the influence of the sympathetic rather than the parasympathetic system. The lack of
effects on HF HRV in our study suggests that sound exposure during recovery may not have a strong
influence on parasympathetic activity, at least not with the exposures and the physiologic indexes used
in the current experiment.
Our study used a small set of environmental sounds of short duration, which limits the
generalizability of the results. The nature sound used in the experiment had a relatively high sound
pressure level (50 dBA). The effect of natural sound environments on stress recovery may be greater in
situations with longer exposure times and with lower sound pressure levels commonly found in
recreational and rural areas outside cities. In city parks and other urban outdoor areas, the sound
environment is typically a mix of sound from nature sounds and traffic noise. Based on the present
results, it seems plausible to speculate that recovery from sympathetic activation in such areas would
be less effective than in areas undisturbed by noise.
5. Conclusions
The present results suggest that after psychological stress, physiological recovery of sympathetic
activation is faster during exposure to pleasant nature sounds than to less pleasant noise of lower,
similar, or higher sound pressure level.
Acknowledgements
This research was conducted in the research project Sustaining Acoustic Pleasantness within Rural
and Community Development (SARCADE), funded by the Swedish Research Council FORMAS.
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This article is an open-access article distributed under the terms and conditions of the Creative
Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
... Many studies have shown that emotions can be affected by environmental factors. Favorable soundscapes proved to be capable of reducing stress-related physiological markers; for example, nature sounds produce a higher reduction in skin conductance level than other sounds related to urban contexts (36). As a consequence, natural sounds were indicated as vital factors in easing stress recovery (37). ...
... In the future, more in-depth research on the relationship between physiological indicators and psychological and emotional health will help to better understand people's mental health and emotional health. At the same time, there are many factors that affect emotional health besides temperature, such as sound, vision, heat, smell, etc (36)(37)(38). The coupling effect of multiple factors on emotions can be explored in the future. ...
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The combined effect of global warming and the heat island effect keeps the temperature of cities rising in the summer, seriously threatening the physical and mental health of urban residents. Taking the area within the Sixth Ring Road of Beijing as an example, based on Landsat remote sensing images, meteorological stations, and questionnaires, this study established a relational model between temperature and hostility and then analyzed the changes in the emotional health risk (hostility) in the study area and the mechanism of how outdoor activity duration influences hostility. Results show that: (1) the area within the Sixth Ring Road of Beijing had a higher and higher temperature from 1991 to 2020. Low-temperature areas gradually shrank, and medium- and high-temperature areas extended outwards from the center. (2) The threat of high temperature to residents' hostility gradually intensified—the sphere of influence expanded, low-risk areas quickly turned into medium-high-risk areas, and the level of hostility risk increased. Level 1 risk areas of hostility had the most obvious reduction—a 74.33% reduction in area proportion; meanwhile, Level 3 risk areas had the most significant growth—a 50.41% increase in area proportion. (3) In the first 120 min of outdoor activities under high temperature, residents' hostility was negatively correlated with outdoor activity duration; after more than 120 min, hostility became positively correlated with duration. Therefore, figuring out how temperature changes influence human emotions is of great significance to improving the living environment and health level of residents. This study attempts to (1) explore the impact of temperature changes and outdoor activity duration on hostility, (2) evaluate residents' emotional health risk levels affected by high temperature, and (3) provide a theoretical basis for the early warning mechanism of emotional health risk and the planning of healthy cities.
... In contrast to an acoustic environment, a soundscape is a deliberate composition of the aforementioned three features by a designer's vision [53]. With the increasing awareness of acoustic environments [53], cities start to actively monitor noise pollution [9], as noise is related to health problems [48,74], whereas natural sounds have been found to provide health benefits [2,10,22]. ...
... The existing body of related works shows that soundscapes and footsteps contribute to the immersion in virtual worlds [56], in which footstep sounds also influence walking behavior [47,62,67,84,92,95,97,101]. There is a positive influence of natural sounds [2,10,22,23] on health, and augmented footsteps sounds may serve as an unobtrusive feedback channel [36,71,79]. In addition, soundscapes themselves can provide special cues about the environment [15,21,32,45,83]. ...
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Urban environments are often characterized by loud and annoying sounds. Noise-cancelling headphones can suppress negative influences and superimpose the acoustic environment with audio-augmented realities (AAR). So far, AAR exhibited limited interactivity, e. g., being influenced by the location of the listener. In this paper we explore the superimposition of synchronized, augmented footstep sounds in urban AAR environments with noise-cancelling headphones. In an online survey, participants rated different soundscapes and sound augmentations. This served as a basis for selecting and designing soundscapes and augmentations for a subsequent in-situ field study in an urban environment with 16 participants. We found that the synchronous footstep feedback of our application EnvironZen contributes to creating a relaxing and immersive soundscape. Furthermore, we found that slightly delaying footstep feedback can be used to slow down walking and that particular footstep sounds can serve as intuitive navigation cues.
... Davis and Nussbaum (2008) stated that the involuntary canters in the central nervous system can be stimulated by sounds that are transmitted to the higher levels of the brain and influence emotional and abstract thought. Alvarsson et al. (2010) demonstrated significant skin conductance level recovery after a psychological stressor in those who listened to natural sounds. In addition, restoration effects of nature sounds in mood recovery among respondents exposed to nature sounds concurrent with anxietyreducing effects (Benfield et al., 2014); and reduction in sympathetic activity and an increase in parasympathetic activity (Alvarsson et al., 2010;Annerstedt et al., 2013) Demographically, all participants in this study were Malays except for one Indian, but all were Muslims. ...
... Alvarsson et al. (2010) demonstrated significant skin conductance level recovery after a psychological stressor in those who listened to natural sounds. In addition, restoration effects of nature sounds in mood recovery among respondents exposed to nature sounds concurrent with anxietyreducing effects (Benfield et al., 2014); and reduction in sympathetic activity and an increase in parasympathetic activity (Alvarsson et al., 2010;Annerstedt et al., 2013) Demographically, all participants in this study were Malays except for one Indian, but all were Muslims. This reason could be because the surrounding population is mostly Malays, and the hospital itself is affiliated with the International Islamic University, which naturally would attract more Muslim patients. ...
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This study aimed to compare the effectiveness between listening to Quran and nature sounds on preoperative anxiety and physiological parameters. Using systematic random sampling, a randomized controlled trial study was conducted among 81 patients, which comprised of male and female patients allocated into three equal groups, that is, Quran recitation group, nature sounds group, and a control group. Preoperative state anxiety was measured using the State-Trait Anxiety Inventory (Embong, 2018), and physiological parameters were recorded before and after the intervention. After the intervention, the analysis within-subjects showed significant improvement in heart rate, respiratory rate, and state anxiety. However, post-hoc test showed that reduction in the mean state anxiety scores in all groups was the only significant factor. Paired analysis showed that only mean state anxiety level of nature sounds group has a significant reduction in comparison to control group; whereas there was nonsignificant difference in state anxiety of other paired groups when compared between both intervened groups and between Quran group and control group. The result concluded that listening to either the Quran or nature sounds were effective in reducing preoperative anxiety, however head-to-head comparison found no significant difference.
... Furthermore, they can warn us from potential dangers (e.g., alarm sounds, alerting calls) or be a source of aesthetic experience (e.g., music, nature sounds; Shafiro, 2008). A growing body of research also suggests that listening to natural sounds can contribute to listener's sense of wellbeing and aid in psychological restoration (Alvarsson, Wiens, & Nilsson, 2010), whereas prolonged exposure to excessive noise has detrimental effects on mental and physical health (Basner et al., 2014). ...
Thesis
Auditory categorisation is a function of sensory perception which allows humans to generalise across many different sounds present in the environment and classify them into behaviourally relevant categories. These categories cover not only the variance of acoustic properties of the signal but also a wide variety of sound sources. However, it is unclear to what extent the acoustic structure of sound is associated with, and conveys, different facets of semantic category information. Whether people use such data and what drives their decisions when both acoustic and semantic information about the sound is available, also remains unknown. To answer these questions, we used the existing methods broadly practised in linguistics, acoustics and cognitive science, and bridged these domains by delineating their shared space. Firstly, we took a model-free exploratory approach to examine the underlying structure and inherent patterns in our dataset. To this end, we ran principal components, clustering and multidimensional scaling analyses. At the same time, we drew sound labels’ semantic space topography based on corpus-based word embeddings vectors. We then built an LDA model predicting class membership and compared the model-free approach and model predictions with the actual taxonomy. Finally, by conducting a series of web-based behavioural experiments, we investigated whether acoustic and semantic topographies relate to perceptual judgements. This analysis pipeline showed that natural sound categories could be successfully predicted based on the acoustic information alone and that perception of natural sound categories has some acoustic grounding. Results from our studies help to recognise the role of physical sound characteristics and their meaning in the process of sound perception and give an invaluable insight into the mechanisms governing the machine-based and human classifications.
... [10][11][12] A study has also demonstrated that exposure to nature sound was reported to facilitate recovery from sympathetic activation. 13 Although individual stress management strategies appear to be effective in reducing stress, a multidisciplinary approach may be more effective than any single strategy on its own. 14 A notable intervention for alleviating work-related stress is the presence of a natural or forest environment, which is highly correlated with the quality of life. ...
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Background The effect of a forest therapy in a natural environment noted that the forest therapy induced a state of relaxation among workers, thereby decreasing cortisol levels and work-related stress. Objective The primary objective of this study is to determine the effects of the forest therapy for employees in the manufacturing industry on psychological stress responds, stress hormone and heart rate variability (HRV). The secondary objective is to determine the effects of the forest therapy for employees in the manufacturing industry on cytotoxic activity of natural killer (NK) cells, health-related quality of life and mood states compare to urban untreated and remained in urban environment. Methods Forty-two employees were recruited from a single workplace located in Incheon city, Republic of Korea. Participants were allocated to either an experimental group (n= 21), wherein they participated in the forest therapy and or a control group (n= 21), wherein they were given no treatment. Participants were assigned to these groups on a randomized, open-label basis. Pre and post-test measures of natural killer (NK) cell activity, salivary cortisol, heart rate variability (HRV), health-related quality of life, stress response, and mood states were taken for both groups. Results The results showed that participants who took part in the forest therapy showed greater physiological improvement when compared to those in the control group, as indicated by a significant increase in some HRV measures. The forest therapy also contributed to a significantly greater decrease in work-related stress symptoms and a significantly greater improvement in health-related quality of life and mood states compared to participants in the control group. Conclusions These results may suggest that the forest therapy could be an effective means of relaxation technique, reducing stress and leads to an increase in positive mood for employees in the manufacturing industry.
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The experience of nature can bring various psychological benefits, including attention restoration, stress recovery, and mood improvement. Application of biophilic design principles to incorporate various forms of natural elements in workplaces can improve their occupants’ productivity and psychological well-being. However, most of the research regarding restorative environments to date has been focused exclusively on their visual contents. The role of thermal perception in psychological restorative processes has largely been overlooked. This paper examines the restorative benefits of thermal pleasure experiences in the context workplace semi-outdoor environments. A pre-and-post-test experiment was conducted to compare the restorative effects of a workplace semi-outdoor space presenting two distinct thermal scenarios, one devoid of thermally adaptive opportunities, just direct sunlight exposure, and the other condition including the adaptive opportunity for subjects to select between direct sunlight or shade. The experiment used a multisensory virtual reality method to simulate the dynamic environmental conditions of an actual semi-outdoor space located in Melbourne Australia. Forty-two university students participated the experiment. The results showed a statistically significant association between thermal pleasure/thermal adaptive opportunity and restorative benefits. These findings suggest that thermal pleasure contributes to the restorative properties of workplace semi-outdoor environments, specifically in relation to attention restoration, stress recovery, and mood improvement. The study bridges the research fields of thermal comfort, virtual reality, and psychological restoration. The implementation of adaptive thermal comfort and alliesthesia concepts in semi-outdoor environmental design may add more than comfort improvements, but also broader psychological benefits that are relevant to an increasingly urbanised population.
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Sound has enormous influence on human organism. Different types of sound vibrations have both positive and negative effects on peoples health. This review highlights that sound is important factor for health regulation with the emphasis on cognitive functions and mental activity. Also, we describe strategies of using sound in treatment of neurological diseases, anxiety disorders, depressions, and social rehabilitation. Sound influence and its exploit are examined on different levels: ultrasound, infrasound, white noise, music and nature sounds. Finally, our review has shown sound great potential in treatment of neurodegenerative and psychiatric disorders, carpal tunnel syndrome, postoperative rehabilitation, and cognitive functions improvement. We propose the implementation of acoustic monitoring and music therapy as substantial components of rehabilitation medicine.
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The goal of this study is to investigate the psychophysiological effects of traffic sounds in urban green spaces. In a laboratory experiment, psychological and physiological responses to four traffic sounds were measured, including road, conventional train, high-speed train, and tram. The findings demonstrated that traffic sounds had significant detrimental psychological and physiological effects. In terms of psychological responses, the peak sound level outperformed the equivalent sound level in determining the psychological impact of traffic sounds. The physiological effects of traffic sounds were shown to be significantly influenced by sound type and sound level. The physiological response to the high-speed train sound differed significantly from the other three traffic sounds. The physiological effects of road traffic sounds were found to be unrelated to the sound level. On the contrary, as for the railway sounds, the change in sound level was observed to have a significant impact on the participants’ physiological indicators.
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Shifting the focus from fear, guilt, and indignation related to deteriorating environmental quality, the authors hypothesized that people who see greater potential for restorative experiences in natural environments also do more to protect them by behaving ecologically, as with recycling or reduced driving. University students (N = 488) rated a familiar freshwater marsh in terms of being away, fascination, coherence, and compatibility, qualities of restorative person-environment transactions described in attention restoration theory. They also reported on their performance of various ecological behaviors. The authors tested a structural equation model with data from a randomly drawn subset of participants and then confirmed it with the data from a second subset. For the combined subsets, perceptions of the restorative qualities predicted 23% of the variance in general ecological behavior. As the only direct predictor, fascination mediated the influences of coherence, being away, and compatibility.
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According to guidelines proposed in Sweden, at least 80% of the visitors in quiet areas should perceive the sound environment as good. This was the starting point for a questionnaire study on "soundscape quality" in four suburban green areas and in four city parks. The soundscapes in the suburban areas were completely dominated by sounds from nature (e.g., bird song and sounds from water), whereas traffic noise was a main component of the city-park soundscapes. Measured equivalent sound levels (from all sources) ranged from 42 to 50 dBA in the suburban green areas, and from 49 to 60 dBA in the city parks (LAeq, 15min). "Soundscape quality" was assessed by a five-point bipolar category scale. Among the respondents, 84-100% in the suburban green areas and 53-65% in the city parks assessed the soundscape as "Good" or "Very good". Thus, all suburban green areas but none of the city parks reached the stipulated goal (at least 80%). The soundcape quality was confirmed by attribute profiling using a set of 12 adjectives. Based on the visitor's responses, it is concluded that good soundscape quality can only be achieved if the traffic noise exposure in suburban green areas and city parks during day time is below 50 dBA.
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Reviews the book, Psychophysiology: Human behavior and physiological response (4th ed.) by John L. Andreassi (see record 2000-07165-000). This is the fourth edition of a well-known and highly acclaimed book. Although the author modestly states, "The plan of this book is to provide students with elementary information...," the book is almost an encyclopaedic account of this extremely extensive field. Given this comprehensiveness, the book represents an excellent introduction and overview to the whole field of psychophysiology. There are two introductory chapters, the first of which provides a general introduction to the field of psychophysiology, starting very conventionally with definitions and followed by a short historical account. The following chapter provides information on the basic anatomy and physiology of the nervous system, as well as the principles behind the main techniques used. The remaining 17 chapters are grouped into three main conceptual areas: (1) measures of central nervous system activity, (2) measures of the activity of behaviourally relevant peripheral systems, and (3) applications and methodological issues including an appendix dealing with the extremely important issue of laboratory safety. Andreassi has written a comprehensive guide on research methods in psychophysiology, clearly written and very suitable for the group for whom the book is primarily intended: students of behavioural science. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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The statistical power of a test of significance for the difference among means is dependent upon a number of factors, among them the presence of a covariate, which often serves to increase power, as well as measurement error, which reduces power. Formulas are provided for adjusting Cohen's (1977) f value for these two sources of variability. These adjusted f values can then be used with Cohen's power tables. An example of the use of these formulas in the planning stage of a study is given, followed by a description of the complex nature of the relationship between power and covariance and measurement error.
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discuss specific theoretical and methodological issues related to the use of psychophysiological measures of arousal / describe state-of-the-art electrodermal and cardiovascular measurement techniques / emphasize the use of patterns of electrodermal and cardiovascular responses as indexes of arousal specifying an arousal construct / maintaining a psychophysiologically consonant experimental situation / multiple psychophysiological response measures / continuous measurement (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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Individual differences in preferences to photographs were explored based on an alternative framework. This framework predicts that the primary difference between individuals in this respect is their ability to process photographic information, which in turn influences their preferences. Chiefly, people with well-developed schemes in photography (e.g., photo professionals) should have a higher ability to process photographic information than people with less developed schemes (e.g., psychology students). Consequently, people with well-developed schemes in photography should prefer photographs that are relatively more demanding to process. Ten psychology students and 5 photo professionals assessed 32 photographs on six general concepts: Preference, Hedonic Tone, Expressiveness, Familiarity, Uncertainty, and Dynamics. As predicted, photo professionals had a higher ability to process photographic information and preferred photographs that were relatively uncertain and unfamiliar. These results are in concordance with previous research and give strong support to the utility of the present framework in experimental aesthetics. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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A considerable body of folklore and scientific research alludes to the efficacy of the vernacular environment to influence both aesthetic experience and general well-being. To examine explicitly whether stress recovery and/or immunization varies as a function of the roadside environment, 160 college-age participants, both male and female, viewed one of four different video-taped simulated drives through outdoor environments immediately following and preceding mildly stressful events. Overall, it was anticipated that participants who viewed artifact-dominated drives, relative to participants who viewed nature-dominated drives, would show greater autonomic activity indicative of stress (e.g. elevated blood pressure and electrodermal activity), as well as show altered somatic activity indicative of greater negative affect (e.g. elevated electromyographic (EMG) activity over the brow region and decreased activity over the cheek region). In addition, it was expected that participants who viewed nature-dominated drives would experience quicker recovery from stress and greater immunization to subsequent stress than participants who viewed artifact-dominated drives. The overall pattern of results is consistent with both hypotheses and the findings are interpreted to support postulating a sympathetic-specific mechanism that underlies the effect of nature on stress recovery and immunization.
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Urbanicity presents a challenge for the pursuit of sustainability. High settlement density may offer some environmental, economic, and social advantages, but it can impose psychological demands that people find excessive. These demands of urban life have stimulated a desire for contact with nature through suburban residence, leading to planning and transportation practices that have profound implications for the pursuit of sustainability. Some might dismiss people's desire for contact with nature as the result of an anti-urban bias in conjunction with a romantic view of nature. However, research in environmental psychology suggests that people's desire for contact with nature serves an important adaptive function, namely, psychological restoration. Based on this insight, we offer a perspective on an underlying practical challenge: designing communities that balance settlement density with satisfactory access to nature experience. We discuss research on four issues: how people tend to believe that nature is restorative; how restoration needs and beliefs shape environmental preferences; how well people actually achieve restoration in urban and natural environments; and how contact with nature can promote health. In closing, we consider urban nature as a design option that promotes urban sustainability.
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We tested the hypothesis that exposure to nature stimuli restores depleted voluntary attention capacity and affects selective attention. Before viewing a video of either a natural or an urban environment, 28 subjects first completed a proofreading task to induce mental load and then performed Posner's attention-orienting task. After viewing the video they performed the attention-orienting task a second time. Cardiac inter-beat interval (IBI) was measured continuously to index autonomic arousal. Before the video both groups reacted faster to validly versus invalidly cued targets in the attention-orienting task. After the video, the urban group was still faster on validly versus invalidly cued trials, but in the nature group this difference disappeared. During the video the nature group had a longer mean IBI (lower heart rate) measured as the difference from baseline than the urban group. The results suggest that reduced autonomic arousal during the video engendered less spatially selective attention in the nature group compared to the urban group.