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Acoustic performance of woven fabrics in relation to
structural parameters and air permeability
Parham Soltani
a
& Mohammad Zarrebini
b
a
Department of Textile Engineering , Amirkabir University of Technology , Tehran , Iran
b
Department of Textile Engineering , Isfahan University of Technology , Isfahan , Iran
Published online: 25 Feb 2013.
To cite this article: Parham Soltani & Mohammad Zarrebini (2013) Acoustic performance of woven fabrics in
relation to structural parameters and air permeability, Journal of The Textile Institute, 104:9, 1011-1016, DOI:
10.1080/00405000.2013.771427
To link to this article: http://dx.doi.org/10.1080/00405000.2013.771427
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Acoustic performance of woven fabrics in relation to structural parameters and air
permeability
Parham Soltani
a
and Mohammad Zarrebini
b
*
a
Department of Textile Engineering, Amirkabir University of Technology, Tehran, Iran;
b
Department of Textile Engineering,
Isfahan University of Technology, Isfahan, Iran
(Received 13 November 2012; final version received 25 January 2013)
This work deals with the study of the acoustic characteristics of woven fabrics in relation to fabric structural
parameters and air permeability. In order to achieve the objectives of the research, sound absorption coefficient of
woven fabric samples was determined via impedance tube method. Samples with various pick densities and yarn
twist were used. The effect of fabric thickness was analyzed using three and six layered test samples. Results
showed that, while for all samples the minimum values of sound absorption were observed at frequency bands of
250 and 2000 Hz, the maximum sound absorption occurred at the frequency of 1000 Hz. Results also indicated
that fabrics woven at pick density of 30 thread/cm exhibited higher sound absorption than fabrics woven at other
pick densities. It was found that, noise reduction coefficient of three and six layered samples, woven at low pick
densities showed significant increases in comparison to those woven at high pick densities. It was also established
that samples woven with lower weft yarn twist absorb sound wave more efficiently. It was concluded that fabric
air permeability can be used as a criterion of sound absorption behavior of woven fabrics.
Keywords: sound absorption coefficient; noise reduction coefficient; air permeability; pick density; yarn twist;
fabric thickness
Introduction
Woven fabrics are generally least effective as far as
sound absorption is concerned. However, sufficient air
space is provided at the back of freely hanged woven
fabric so that sound absorption ability of the fabric is
greatly enhanced (Soltani & Zarrebini, 2012). Gener-
ally, the following four phenomena can be held
responsible for absorption of sound by woven fabrics:
(1) Internal visco-thermal dissipative effects. These
are mainly dominated by visco-inertial effects
due to the negligible thickness of fabric.
(2) Flow distortion effects generated on both sides
of the fabric.
(3) Acoustic resonance in the cavity at the back of
sample. This influences fabric response to nor-
mal incidence plane wave.
(4) Bending vibrations of the fabric (Jaouen &
Becot, 2011).
So far there is no general consensus on the principal
factors in determining the sound absorption perfor-
mance of textiles. Work of Bies and Hansen (2009)
explains that flow resistance is the most influential
factor in determining how a fabric acts as a sound
absorbing material. Fahy and Walker (1998) as well as
Ver and Beranek (2006) have reported that flow resis-
tance, porosity, air permeability, and tortuosity (i.e. the
structure factor) have the greatest impact on the acous-
tic performance of textile materials. Dias, Monaragala,
Needham, and Lay (2007) analyzed sound absorption
of tuck spacer fabrics. It was found that sound
absorbency of the fabric increases with both airflow
resistivity and fabric thickness. It has been reported
that, fabric porosity is inversely proportional to the
airflow resistivity. Hence, it was concluded that varia-
tion in fabric sound absorption property is inversely
proportional to fabric porosity. Yang and Yu (2011)
investigated the relationship between air permeability
and acoustic performance of nonwovens. It was
stated that nonwoven samples with highest value of
air permeability exhibited inferior acoustic absor-
bency. Additionally, Lee and Chen (2003) have also
demonstrated that apart from flow resistance, porosity,
tortuosity, pore size distribution, and fiber orientation
are also among principal factors that ought to be
considered when designing a textile-based sound
absorbent material. Nute and Slater (1973) modeled
*Corresponding author. Email: zarrebini@cc.iut.ac.ir
The Journal of The Textile Institute, 2013
Vol. 104, No. 9, 1011–1016, http://dx.doi.org/10.1080/00405000.2013.771427
Ó 2013 The Textile Institute
Downloaded by [University of Newcastle (Australia)] at 10:49 20 September 2013
the acoustic performance of the fabrics, and reported
that weight and cover of woven fabrics as independent
factors directly affect transmission loss by the fabric.
However, fabric thickness inversely influences sound
reduction by the fabric particularly at high
frequencies. Na, Lancaster, Casali, and Cho (2007)
concluded that the most influential factors affecting
acoustic performance of textiles are elastic modulus,
thickness, porosity, and flow resistance.
The published literature on the field of textile
acoustic vividly points to the complexities of textile
systems as sound absorbers. It can be seen that while
relevant parameters not only independently influence
the acoustic performance of the sound absorbent
textile system, their interaction also in this respect is
pivotal (Roth, 2010). The present work is in line with
our previous paper (Soltani & Zarrebini, 2012) where
acoustic performance of woven fabrics were analyzed
in terms of fabric fundamental structural parameters
namely fabric weave and weft yarn linear density.
Results revealed that both the fabric porosity and fab-
ric density have profound effect on fabric sound
absorption performance.
It is shown that, fabric air permeability and porosity
are influenced by pick density, weft yarn twist, and fabric
thickness (Ogulata, 2006). Sundaramoorthy, Nallampala-
yam, and Jayaraman (2011) reported that air permeabil-
ity of multilayer fabric system not only decreases
exponentially as the number of layers constituting fabric
thickness increases, but also the rate of decrease is inver-
sely proportional to the number of layers.
There have been a few studies on acoustic
characteristics of woven fabrics in relation to fabric air
permeability. Studies of Zhang (2008) established the
relationship between the maximum sound absorption
and permeability coefficients of both woven and non-
woven fabrics at frequency of 400 Hz. It was stated that
sound absorption coefficient peaks at a certain air per-
meability and then begins to reduce. Jeong, Kim, and
Sohn (2008) investigation on sound absorption coef fi-
cient of poly tetra fluoro ethylene (PTFE) membrane
material disclosed that an acceptable relationship exists
between air permeability and sound absorption coeffi-
cients when the former lies in the range of 5–15 cm
3
/
cm
2
/s. Aso and Kinoshita (1964) investigated the influ-
ence of the flow resistance on sound absorption charac-
teristics of fabrics and established that based on fabric
type there exists two absorbing mechanisms. These
mechanisms were referred to as viscosity resistance and
the resonance. The former prevails if flow resistance
solely depends on air viscosity within a narrow range
of flow speeds.
Despite intensive researches on acoustic perfor-
mance of textiles, there have been few investigations
on sound absorption performance of conventional
woven fabrics. The available literatures emphasize on
the effect of weave type, yarn linear density, yarn
twist, and fabric thickness on sound absorption
coefficient. However, in a woven fabric the combined
effect of these factors in the form of fabric cover
factor must be investigated. Air permeability can be
used as criterion of fabric cover factor, which in turn
is the means by which absorption behavior of woven
fabrics can be investigated. Furthermore, hardly any
trace of scientific published work that encompasses
acoustic performance of layered fabrics in relation to
air permeability can be found. Therefore, the present
work investigates the effect of pick density, weft yarn
twist, and thickness created by layering of test fabrics
on sound absorption coefficient of woven fabrics in
relation to fabric air permeability and porosity.
Experimental
About 38 mm long 1.77 dtex round polyester fibers
were used to produce spun yarns on a Howa ring
spinning frame under the standard condition. Rapier
weaving technology was used to produce the woven
samples. Sound absorption coefficient and air
permeability of plain woven fabric test samples were
determined using impedance tube method and Shirley
FX 3300-5 air permeability tester (Shirley, Manchester,
UK). Air permeability was measured according to
BS5636 test method, at differential pressure of 100 Pa.
Test samples was cut randomly at considerable dis-
tance from fabric selvedges. Using standard compres-
sion tester, thickness of the fabrics was measured at
pressure of 5 g/cm
2
. Sound absorption coefficient of
each test sample was determined using Texsonicmeter
®
(Department of Textile Engineering, Isfahan
University of Technology, Isfahan, Iran) (Soltani &
Zarrebini, 2012), always maintaining airspace of 4 cm
at the back of test samples. The samples are fastened
to one end of tube, and the loud speaker emitting
sound waves of well-defined frequencies is attached to
the other end of the tube. The emitted waves travel
through the tube and are reflected back from the
sample. The reflected waves are received by the micro-
phone. Traces of reflected sound wave by the micro-
phone appear on an oscilloscope. Equations (1) and
(2) were used for calculation of absorbed sound by
test fabric.
a ¼
I
i
I
r
¼ 1
n 1
n þ 1
2
¼
4n
(1 þ n)
2
; (1)
n ¼
P
max
P
min
; (2)
1012 P. Soltani and M. Zarrebini
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where α = sound absorption coefficient; I
i
and
I
r
= intensities of incident and reflected sound waves,
respectively; n = standing wave ratio which is the ratio
of the maximum to minimum pressure of the sound
wave; P
max
and P
min
= maximum and minimum values
of sound wave pressure, respectively (Kundt, 1868).
The mean of sound absorption coefficient values at
frequencies of 250, 500, 1000, and 2000 Hz was used
as fabric noise reduction coefficient (NRC).
Experiments were conducted in the absence of no
peripheral sounds at relative humidity of 55 ± 2% and
ambient temperature of 23 ± 2°C. Sound absorption
and air permeability tests were repeated 10 times for
each sample.
Results and discussion
Effect of pick density on sound absorption coefficient
In order to confirm the effect of fabric pick density
variation on sound absorption performance of fabric,
normal incident sound absorption coefficient was mea-
sured. Six samples of plain fabrics having identical
warp density of 26 thread/cm and pick densities of 15,
20, 25, 30, 35, and 41 thread/cm were woven. Spun
yarns with linear densities of 29 and 24 tex at twist
levels of 557 and 480 tpm were used as warp and
weft, respectively.
Fabric structural parameters and measured air per-
meability values are shown in Table 1.
Pick density is defined as the parameter denoting
the number of filling yarns per unit length along the
fabric length. This parameter can affect fabric overall
density. The effect of pick density on fabric sound
absorption coefficient and NRC is shown in Figures 1
and 2.
Considering Figure 1, it can be stated that, absorp-
tion coefficient of the test samples lies in the range of
0.04–0.47. It is also apparent that, for all samples
while the maximum value of absorption coefficient
occurs at frequency of 1000 Hz, the minimum value
of absorption coefficient is obtained at frequency
bands of 250 and 2000 Hz. This is in agreement with
the findings of Zhang (2008) who showed that for
cotton plain fabrics with thickness of 0.39 mm, the
maximum sound absorption occurs at the frequency of
1000 Hz and the minimum takes place at frequencies
of 200 and 1800 Hz. Moreover, the results are com-
pletely compatible to fi ndings of Aso and Kinoshita
(1963, 1964) who observed that for plain and
herring-bone weave samples at air space of 6 cm, the
maximum sound absorption occurs at frequency of
1000 and the minimum takes place at frequency bands
of 250 and 2000 Hz. Referring to Figure 1 it can be
observed that an increase in fabric pick density gener-
ally leads to slight enhancement of sound absorption
ability of woven fabrics at low frequencies. It is also
shown that fabric sound absorption ability tends to
increase up to pick density of 30 thread/cm beyond
which it reduces. At low fabric pick density, minimal
sound absorption occurs. This is due to the ease of
sound waves through the fabric. At higher fabric pick
density such as 35 and 41 threads/cm, smaller fabric
pores are created. This results in higher fabric overall
density which in turn causes a greater portion of the
incident sound to be reflected from the fabric, thus
preventing the transmission of sound through the
material, hence decreasing absorption of sound by the
fabric (Kuttruff, 2007). Poor fabric sound absorption
at low frequency bands is due to complete
transmission of sound through fabrics which
technically can be described as having a tissue-like
thickness.
Three general mechanisms for absorption of sound
by fibrous assemblies have been defined by Aso and
Kinoshita (1963). The first mechanism which is
known as viscosity resistance absorption concerns
with low sound absorption at low frequencies. At
high-pitched tones absorption is quite considerable.
Upon sound wave striking a fibrous assembly, vibra-
tion of entrapped air within narrow air spaces of the
assembly occurs due to sound pressure. Sound wave
Table 1. Test samples structural parameters.
Weft
density
(thread/
cm)
Fabric
weight
(g/m
2
)
Fabric
thickness
(mm)
Fabric
density
(g/cm
3
)
Air
permeability
(cm
3
/cm
2
/s)
15 108 0.42 0.25 48
20 122 0.42 0.29 37
25 136 0.43 0.31 29
30 149 0.46 0.32 24
35 165 0.48 0.34 20
41 184 0.51 0.36 15
Figure 1. Effect of pick density on absorption coefficient.
The Journal of The Textile Institute 1013
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energy reduces due to the frictional resistance of the
fibers and the vibrating air. When sound energy is
converted to heat by air viscosity due to relative
movement of air on fibers, the absorption mechanism
is also referred to as viscosity resistance. In the second
mechanism, absorption peaks out at low frequencies.
At high-frequency range, absorption coefficient
improves as frequency is increased. This mechanism
differs from the absorption characteristics of resonance
absorption obtained when airtight materials, such as a
pulp broad or plywood are placed at a distance from a
solid wall. The peak at a low frequency is generally
presumed to be due to resonance effect. The reduction
of absorption coefficient at the frequencies of 1500
and 2000 Hz can be due to occurrence of coincidence
dip phenomenon (Ver & Beranek, 2006). This
phenomenon is commonly known as the critical fre-
quency which can severely limits sound absorption
ability of the sample. This phenomenon occurs when
the incident and reflected sound waves are in phase.
The third mechanism which shows peakless resonance
absorption lies between the first and second absorption
mechanisms. This is due to the fact that at frequencies
higher than that of resonance, absorption coefficient is
greater than that of the viscosity resistance (Aso &
Kinoshita, 1963). The frequency at which the maxi-
mum sound absorption occurs depends upon the air
space at the back of samples (Aso & Kinoshita, 1964;
Soltani & Zarrebini, 2012). Thus, in this work natu-
rally maximum sound absorption for all samples
occurs at a particular frequency of 1000 Hz due con-
stant 4 cm air space at the back of test samples.
As shown by the group 1 columns in Figure 2,
fabric woven at pick density of 30 thread/cm enjoys
the maximum sound absorption. At this value of pick
density, fabric overall density and air permeability are
0.32 gr/cm
3
and 24 cm
3
/cm
2
/s, respectively. Results
show that sound absorption ability of woven fabrics is
influenced by fabric overall density, porosity, and air
permeability.
Table 1 shows that fabric air permeability is
decreased as pick density increases. In order to
investigate the effect of pick density on fabric sound
absorption performance, it is necessary to evaluate the
variation of fabric NRC value in relation to fabric air
permeability. The effect of fabric air permeability on
sound absorption performance of samples given in
Table 1 is shown in Figure 3.
As shown in Figure 3, NRC reaches its peak value
in the fabric air permeability range of 20–29 cm
3
/cm
2
/
s. NRC value is low at higher values of fabric air
permeability which corresponds to low fabric pick
density in the range of 15–20 threads/cm. This is due
to the fact at low pick density almost complete
transmission of sound through the fabric occurs. Fur-
thermore, at mid-frequency and high-frequency bands,
the sound absorption coefficients of the fabrics with
air permeability lower than 20 cm
3
/cm
2
/s are relatively
low. The reduction in NRC value at latter air perme-
ability range is due to the very compact fabric surface
that prevent transmission of sound wave through the
fabric, thus a great proportion of incident sound waves
is reflected.
In order to establish the effect of fabric thickness
and in-depth evaluation of the effect of pick density
on sound absorption coefficient of woven fabrics,
thicker test samples were prepared by layering
technique. The sample preparation was carried out
according to the procedure described in (Soltani &
Zarrebini, 2012). The effect of fabric thickness using
layering technique on fabric NRC is depicted in
Figure 2, where comparison between NRC values of
single, three and six layered samples are illustrated.
As can be seen, multilayered fabrics exhibit signifi-
cantly higher values of NRC in comparison to single
layered. Increasing the number of layers causes an
increase in both thickness and resistance to air flow of
the samples. Therefore, in multilayered fabric system,
increase in air flow resistivity and the volume of
Figure 2. Effect of pick density and number of layers on
NRC.
Figure 3. Effect of air permeability on NRC.
1014 P. Soltani and M. Zarrebini
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entrapped air are responsible for the observed increase
in the values of NRC. The effect of layering on sound
absorption is well compatible with findings of previ-
ous researchers that have established that the sound
absorption coefficient increases as thickness of absorb-
ing material increases (Hanna & Kandil, 1991).
As Figure 2 shows, as far as layered samples are
concerned, at lower fabric pick densities increase in
NRC value is higher than corresponding NRC value at
higher fabric pick densities. This is confirmed by
Figure 4 that shows the hyperbolic relation of fabric air
permeability and number of layers in multilayered
fabric system. As can be seen in Figure 4, reduction in
air permeability of the samples with higher number of
layers woven at lower fabric pick densities is more pro-
nounced than similarly layered sample woven at higher
fabric pick densities. It is also interesting to note that,
three and six layered samples woven at pick density of
25 thread/cm yield a higher NRC than the similar
samples woven at pick density of 30 thread/cm. This
phenomenon can be justified by considering that, upon
reaching the fabric surface depending on fabric charac-
teristics, the incident sound wave is partially absorbed,
transmitted or reflected. Yarn intersection points in the
fabric act as frictional elements that resist sound wave
propagation through the fabric. Fabric internal tortuos-
ity causes sound wave amplitude to decrease. This in
turn leads to conversion of sound energy into heat. As
far as layered samples are concerned, the amount of
entrapped air within the samples woven with lower pick
densities is higher than corresponding values in samples
woven at higher pick densities. This improves absorp-
tion of sound by the fabrics. However, at high pick
densities, increase in cover factor hinders sound
transmission through the fabric, thus sound reflection
from the fabric is increased.
It must be clearly stated that, fabric porosity simul-
taneously governs both air permeability and sound
absorption of woven fabrics. The effect of fabric
porosity on sound absorption coefficient of woven
fabrics was thoroughly investigated in our previous
study (Soltani & Zarrebini, 2012). However, it must
be noted that layered sound absorbing system contains
voids where air is entrapped. These voids affect sound
absorbency of the layered fabric system. Conse-
quently, air permeability should be regarded as the
preferred criterion in determination of acoustic
performance of woven fabrics. For this reason, in the
present work, the relation between air permeability
and sound absorption of woven fabrics is analyzed.
Effect of weft yarn twist on sound absorption
coefficient
In order to analyze the effect of weft yarn twist on
sound absorption coefficient, plain woven fabrics with
pick and warp densities of 25 and 26 thread/cm were
tested. Polyester yarns of 24 tex at twist level of 480,
557, 605, 670, 728, 780, and 843 tpm were used as
weft yarn in the fabric samples. Polyester spun yarns
with linear densities of 29 tex at twist level of 557 tpm
were used as warp yarn.
Variation of fabric absorption coefficient with
sound frequency at various weft yarn twist is depicted
in Figure 5. Due to similarity of curves at twist level
of 843 and 780 tpm with that of 728 tpm, the results
of formers are not shown. Results indicate that gener-
ally for most samples absorption coefficient lies in
range of 0.061–0.401. However, for all samples maxi-
mum value of absorption coefficient occurs at fre-
quency of 1000 Hz. As it can be observed in Figure 6,
fabric NRC decreases as weft yarn twist is increased.
It must be pointed out that, up to twist level of
780 tpm, fabric air permeability is generally increased.
However, fabric air permeability beyond twist level of
780 tpm tends to decrease slightly. The increase in
yarn twist results in increases in yarn compactness.
This in turn reduces both fabric cover and the amount
of voids in the yarns, thus the observed reduction in
fabric NRC. Further increase in yarn twist maximizes
yarn compactness that corresponds to minimum
Figure 4. Effect of number of layers on air permeability.
Figure 5. Effect of weft yarn twist on absorption
coefficient.
The Journal of The Textile Institute 1015
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amount of voids in the yarn. Therefore, no significant
change is observed in fabric air permeability as the
yarn twist is increased from 670 to 780 tpm. However,
partial reduction in fabric air permeability at yarn twist
of 843 can be attributed to increases in yarn hairiness
as a result of fiber breakage. Figure 6 points to exis-
tence of an inverse relation between air permeability
and NRC of woven fabrics. Experiments conducted
using woven fabrics of other weaves such as 2/1 twill,
3/1 twill, 2/2 twill, rips, and satin yielded similar
results as far as weft yarn twist was concerned.
It must be pointed out that fiber related parameters
individually or collectively can influence air perme-
ability of woven fabrics. In this study, the effect of
these factors on sound absorbency of the woven fabric
were not considered.
Conclusion
Despite significantly lower sound absorption
coefficient of woven fabrics in comparison to those of
nonwoven textiles, the former in certain applications
where latter due to both technical and economical can-
not be used are preferred. Additionally, provided an
optimal airspace is allowed at the back of sound
absorbing system then woven fabrics are more effec-
tive means of sound absorption.
The effect of fabric pick density, fabric thickness
created by layering technique and weft yarn twist was
analyzed. The results indicate that sound absorption
coefficient of woven fabrics is dependent on the above
mentioned variables. For a given weft yarn linear den-
sity, fabric woven with pick density of 30 thread/cm
absorbs more sound than other fabrics. It was found
that six layered samples woven at pick density of
25 thread/cm enjoyed higher NRC than similar fabrics
woven at other pick densities. It is concluded that the
rate of increase in NRC of layered fabrics is higher
for samples woven at low pick densities. Results show
that as weft yarn twist is increased, fabric absorption
coefficient is decreased. It can be stated that the higher
rate of NRC increase in fabrics woven at low weft
yarn twist is confirmed by the lower air permeability
of these fabrics.
References
Aso, S. & Kinoshita, R. (1963). Absorption of sound wave
by fabrics, part 1: Absorption mechanism. Textile
Machinery Society of Japan, 8,32–39.
Aso, S. & Kinoshita, R. (1964). Absorption of sound wave
by fabrics, part 3: Flow resistance. Textile Machinery
Society of Japan, 10, 236–241.
Bies, D. A. & Hansen, C. H. (2009). Engineering noise
control: Theory and practice (2nd ed.). New York:
Taylor & Francis.
Dias, T., Monaragala, R., Needham, P., & Lay, E. (2007).
Analysis of sound absorption of tuck spacer fabrics to
reduce automotive noise. Measurement Science and
Technology, 18, 2657–2666.
Fahy, F. & Walker, J. G. (1998). Fundamentals of noise and
vibration. London: E & FN Spon.
Hanna, Y. I. & Kandil, M. M. (1991). Sound absorbing
double curtains from local textile materials. Applied
Acoustics, 34, 281–291.
Jaouen, L. & Becot, F. X. (2011). Acoustical characteriza-
tion of perforated facings. Journal of Acoustical Society
of America, 129, 1400–1406.
Jeong, J. H., Kim, J. J., & Sohn, J. Y. (2008, July 6–10).
Sound absorption characteristics of PTFE membrane
material. Paper presented at the 15th International Con-
gress on Sound and Vibration, Korea.
Kundt, A. (1868). Acoustic experiments. Philosophical
Magazine and Journal of Science, 35,41–48.
Kuttruff, H. (2007). Acoustics: An introduction. New York:
Taylor & Francis.
Lee, F. C. & Chen, W. H. (2003). On the acoustic absorp-
tion of multi-layer absorbers with different inner struc-
tures. Journal of Sound and Vibration, 259, 761–777.
Na, Y., Lancaster, J., Casali, J., & Cho, G. (2007). Sound
absorption coefficients of microfiber fabrics by reverbera-
tion room method. Textile Research Journal, 77, 330–335.
Nute, M. E. & Slater, K. (1973). The effect of fabric param-
eters on sound transmission loss. Journal of The Textile
Institute, 64, 652–658.
Ogulata, T. T. (2006). Air permeability of woven fabrics.
Journal of Textile and Apparel, 5,1–10.
Roth, K. M. (2010). Development and evaluation of woven
structures for acoustic systems (Master of Science).
North Carolina State University, Raleigh.
Soltani, P. & Zarrebini, M. (2012). The analysis of acoustical
characteristics and sound absorption coefficient of woven
fabrics. Textile Research Journal, 82
,875–882.
Sundaramoorthy, S., Nallampalayam, P. K., & Jayaraman,
S. (2011). Air permeability of multilayer woven fabric
systems. Journal of The Textile Institute, 102, 189–202.
Ver, I. L. & Beranek, L. L. (2006). Noise and vibration
control engineering: Principles and applications (2nd
ed.). New York: John Wiley & Sons.
Yang, S. & Yu, W. (2011). Air permeability and acoustic
absorbing behavior of nonwovens. Journal of Fiber Bio-
engineering and Informatics, 3, 203–207.
Zhang, X. A. (2008, June–July). The vibration sound
absorption theory of flexible materials. Paper presented
at the Acoustics ‘08, Paris.
Figure 6. Effect of weft yarn twist on NRC and air
permeability.
1016 P. Soltani and M. Zarrebini
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