perceptual effects of noise mitigation
TRANSCRIPT
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Hosanna Workshop Monday, December 10, 2012
Tekniska nämndhuset, Fleminggatan 4, Stockholm, Sweden
Perceptual Effects of Noise Mitigation
Mats NilssonStockholm University
(Group data 30 listeners)
A‐weighted sound pressure level
Perceived loud
ness (P
NE)
42
46
5054
58
62
6670
74
78
48 52 56 60 64 68 72 76 80 84
LargeModerate
Small
Proportion of low-frequency sound
Perceived Loudnessvs. A‐weighted sound pressure level
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2
L*A = LA + 0.4[LC‐LA]
42
46
50
54
58
62
66
70
74
78
52 56 60 64 68 72 76 80 84 88
LargeModerate
Small
Proportion of low-frequency sound
Perceived loud
ness (P
NE)
BarrierNo barrier
No barrier Barrier
LAeq [dB] 82 73LC‐LA [dB] 2 7LA10 [dB] 86 76
LA10‐90 [dB] 13 8LZ [dB] 98 91
sharpness [acum] 4.33 3.09
distance 3.7 m, height 1.25
LevelSpectral contentVariabilityImpulsesTonality
Acoustics and Annoyance
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Auditory Masking
Low‐frequency sounds masks high‐frequency sounds more than the other way around
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Microphone
Feature extraction
SOM
Concept layer
Known information
Classification of sound type
Excitation of possible sound sources
Bias towards plausible sounds
Bias towards known present sounds sources
I.
II.
III.
...
Overview of the biologically inspired sound recognition model
I. Choosing the best featuresII. Self organizing, unsupervised training,
mapping co‐occurrenceIII. Supervised learning of concepts
0 2 4 6 8 10 12 14 16 180
0,4
Concep
t neu
ron activation (AU)
Time (s)Children playingTraffic soundBusPeople talking
Activation of concepts and most probably labels for a passage of sound recorded at the Lyon case study
Notice‐Event ModelDick Botteldooren, Bert De Coensel
Ghent University
0
20
40
60
80
100 Nature soundsHuman soundsTechnological sounds
Proport
ion (
%)
”hea
rd o
ften
” or
”dom
inat
es c
om
ple
tely
”
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Wanted and Unwanted Sounds
Area number(Soundscape quality rank order)
Stockholm park study, 2006
Nilsson & Lindqvist (2006)
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Environmental quality
Nilsson, Jeon, et al. (2012)
Site C
Site
0
.2
.4
.6
.8
1
B
Pro
porti
on ”g
ood”
or ”
very
goo
d”
A EF C D
Overall environment
Visual environment
Soundscape
Tranquility
Site
Tran
quilit
y sc
ore
(95
% C
I)
Multiple regression equation:Tranquility score = constant + 0.41*visual + 0.43*soundscape, R2 = 0.66
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Tranquility
TR = 9.68 + 0.041 NCF – 0.146 Lday + MF
Watts, Pheasant, Horoshenkov, et al. (University of Bradford)
TRAPT (Tranquillity RAting Prediction Tool)
’tranquil spaces’
Audio‐visual interactionsJeon. et al. (2012) Hanyang University
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1. Reduce audibility of unwanted sounds
2. Increase audibility of wanted sounds
3. Improve scenery
Perceptual Effects of Noise Mitigation
Vegetated barrier Lyon
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Measurements
Questionnaires
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Proport
ion (
%)
“ver
y” o
r “e
xtre
mel
y” a
nnoy
ed
q12
Road‐traffic noise annoyance (“ISO‐question”)
Overall sound level (LAeq,4h)
0
20
40
60
80
100
40 45 50 55 60 65
Stockholm park study, 2006
No barrierBarrier
Lyon, 2011
0
20
40
60
80
100
40 45 50 55 60 65
Proport
ion (
%)
good +
very
good s
ound e
nvi
ronm
ent
Overall sound level (LAeq,4h)
q10Stockholm park study, 2006
Quality sound environment
No barrierBarrier
Lyon, 2011
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1/3-octave-band center frequency (Hz)
1/3‐octave‐band soun
d pressure level (dB
)
No barrier ≈ 68 dBA
30
35
40
45
50
55
60
65
70
75
31.5 63 125 250 500 1k 2k 4k 8k 16k
Barrier ≈ 63 dBA
Spectrum with and without barrier
Distance roadside: 4 m, height: 1.25 m
58
60
62
64
66
68
70
72
74
76
No barrier2
4
6
8
10
12
14
16
6
8
10
12
14
16
18
20
22
Barrier No barrier Barrier No barrier Barrier
Level Relative low-frequency content Variability
LAeq
,10m
in(dB)
LCeq
‐LAe
q(dB)
LA10
‐LA
90(dB)
Box-plots of acoustic variables
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Perceived Noise Annoyance
Rule of Thumb: L* = LA + 0.4(LA‐LC)
20
25
30
35
40
45
50
55
60
63 65 67 69 71 73 75 77 79 81 83
No barrierBarrier
A‐weighted sound pressure level [dB(A), LAeq,4s]
Perceived anno
yance
(magnitude
estim
ation scale)
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12
1.0
1.2
1.4
1.6
1.8
2.0
45 50 55 60 65 70 75 80
A‐weighted sound pressure level, dB (LAeq,8s)
Perceive ann
oyance (LogR)
Perceived Noise Annoyance
No barrierBarrier (4.6 m high)
A‐weighted sound pressure level, dB (LAeq,8s)
Perceive ann
oyance (LogR)
Perceived Annoyance
No barrier (200 m distance)Barrier (10‐50 m distance)
1.2
1.3
1.4
1.5
1.6
1.7
46 48 50 52 54 56 58 60
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Tram noise and ground effects
Hard ground
Tram noise recordings, Grenoble 2012
Soft ground
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Pass-by recordings
4 s76 experimental sounds
LAeq,4s
61
62
63
64
65
66
67
68
69
70
71
Close Far
Far track (7 m)
1/96‐octave‐band center frequency (Hz)
1/96
‐octave‐band
SPL (d
B)
1/96‐octave‐band center frequency (Hz)
Close track (4 m)
1/96‐octave‐band spectra
10
15
20
25
30
35
40
45
50
55
60
25 50 100 200 400 800 1600 3200 6400 12800
asphalt close
grass close
10
15
20
25
30
35
40
45
50
55
60
25 50 100 200 400 800 1600 3200 6400 12800
asphalt far
grass far
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Perceived Annoyance
1. Grass versus Asphalt
P(grass m
ore anno
ying
than
asphalt)
Close Far
N = 19 pairs of tram recordings
40 % 12 %
0
.1
.2
.3
.4
.5
.6
.7
2. Pair comparison
LA, R2 = 0.86LA, ground: R2 = 0.95
61 62 63 64 65 66 67 68
A-weighted sound pressure level [dB(A), LAeq,4s]
Grass
Asphalt
Per
ceiv
ed a
nnoy
ance
(p
air c
ompa
rison
sca
le)
50
40
55
60
65
45
35
Verbal reports far distanceHigh frequency (14)Variability (10)Loudness (10)
Summary: Noise Mitigation Psychoacoustics
• Not only level: also time variability and spectral changes
• Spectral changes influences (short‐term) noise annoyance
• dBA Insertion loss as indictor of perceptual change?
• Notice Event modelling (Ghent University)
• Auralization combined measures (CSTB, SU)
• Audio‐visual interactions (Hanyang University)
Further HOSANNA work