The practice and potential of The practice and potential of urban soundscape designurban soundscape design
Jian KangJian KangSchool of Architecture, University of SheffieldSchool of Architecture, University of Sheffield
SOUNDER SPACES: the forgotten side of quality?London Zoo Wednesday 14 March 2007
SOUNDSCAPESOUNDSCAPEon relationships between ear, human being, sound environment andon relationships between ear, human being, sound environment and societysociety
relating to acoustics, aesthetics, anthropology, architecture, erelating to acoustics, aesthetics, anthropology, architecture, ecology, cology, human geography, landscape, linguistics, media arts, musicology,human geography, landscape, linguistics, media arts, musicology,noise control engineering, philosophy, psychology, political scinoise control engineering, philosophy, psychology, political science, ence, religious studies, sociology, and urban planningreligious studies, sociology, and urban planning
From noise control to soundscapes … …More people from various sectors consider soundscapes ….
SchaferSchafer
science, engineering, social science, humanity and art
OutlineOutline I. SOUNDSCAPE ANALYSIS & EVALUATION I. SOUNDSCAPE ANALYSIS & EVALUATION -- typical resultstypical results
A large scale survey across Europe and ChinaA large scale survey across Europe and ChinaStatistical analysisStatistical analysisSemantic differential analysisSemantic differential analysis
II. SOUNDSCAPE DESIGN II. SOUNDSCAPE DESIGN –– a systematic approacha systematic approachSystem: factors to be considered: soundscape descriptionfactors to be considered: soundscape descriptionSounds:Sounds: Activities; sound elements: water, musicActivities; sound elements: water, musicSpace: Sound field simulationSound field simulationPeople:People: Social/demographic factors, aSocial/demographic factors, aesthetics & pre-perceptionEnvironment:Environment: Aural/visual interactions, etc Aural/visual interactions, etc Tools:Tools: Design guidance, auralisation, ANN modelDesign guidance, auralisation, ANN model
AimAim
Soundscape in urban open public spacesSoundscape in urban open public spacesFocusFocus
Discuss/explore some key issues in the analysis, evaluation, andDiscuss/explore some key issues in the analysis, evaluation, anddesign potentials for soundscape design potentials for soundscape through our recent worksthrough our recent works
AcknowledgementsAcknowledgements Researchers involved in the Sheffield acoustics group, and project partners
This talk
Part IPart I
SOUNDSCAPE SOUNDSCAPE ANALYSIS AND EVALUATIONANALYSIS AND EVALUATION
Soundscape field survey in EU and ChinaSoundscape field survey in EU and China
14 urban open public spaces of five European countries, 5 14 urban open public spaces of five European countries, 5 in Chinain Chinaoverall physical comfort investigation, including acoustic, overall physical comfort investigation, including acoustic, thermal, lighting, visual, and social aspects thermal, lighting, visual, and social aspects each site 600each site 600--1000 interviews, >10,000 total1000 interviews, >10,000 totalSound level and reverberation measured (Leq10, 50, 90), Sound level and reverberation measured (Leq10, 50, 90), together with other physical indices together with other physical indices
EU
Sheffield China
Relationship between the sound level and subjective evaluation of sound level
Sheffield, UK
The Peace Gardens0.843
The Barkers Pool0.896
1
2
3
4
5
50 60 70 80Leq, dB(A)
Subj
ectiv
e E
valu
atio
n
73
Thessaloniki, Greece
Makedonomahon Square0.452
Kritis Square0.817
1
2
3
4
5
50 60 70 80Leq, dB(A)
Subj
ectiv
e E
valu
atio
n
In urban open public spaces, the
background level, say Leq90, is an
essential index. A lower background
sound level can make people feel quieter,
even when the foreground sounds
reach a rather high level
Statistical analysis of the survey results Statistical analysis of the survey results
Some typical results …
Subjective evaluation of sound level and Subjective evaluation of sound level and acoustic comfortacoustic comfort
1, Very quiet (very comfortable); 2, quiet (comfortable); 3, neither quiet (comfortable) nor noisy (uncomfortable); 4, noisy (uncomfortable); 5, very noisy (very uncomfortable).
R2 = 0.7721
R2 = 0.5413
1
2
3
4
5
50 55 60 65 70 75 80 85Leq, dBA
Soun
d le
vel e
valu
atio
n
1
2
3
4
5
Aco
ustic
com
fort
eva
luat
ion
010203040506070
1 2 3 4 5Evaluation
Perc
enta
ge (%
)
Peace Gardens, Sheffield
Sound Sound PreferencesPreferencesEssential preferencesEssential preferences
Positive attitudes towards natural and culturePositive attitudes towards natural and culture--related sounds.related sounds.MicroMicro-- preferencepreference
0
20
40
60
80
100
10~17 18~24 25~34 35~44 45~54 55~64 >65Age groups
Perc
enta
ge (%
)
Favourable
Annoying0
20
40
60
80
100
10~17 18~24 25~34 35~44 45~54 55~64 >65Age groups
Perc
enta
ge (%
)
Annoying
Favourable
Difference in sound preference between age groups
bird songs car music
MacroMacro--preferencepreferencecultural background and longcultural background and long--term environmental experience play an important role term environmental experience play an important role in peoplein people’’s judgment of sound preference.s judgment of sound preference.
A lim os Thessaloniki Sesto San G iovanni Sheffield K assel
K ara. Square Seashore M aked.
Square K ritis
Square P etazzi Square
IV N ov. Square
P eace G ardens
B arkers Pool
F lorent. Square
B ahns-. p latz
F 27.7 84 .0 74 .7 80 .3 74 .5 N 66.6 14 .8 20 .5 17 .9 22 .4 W ater
A 5 .7 1 .2 4 .8 1 .8 3 .1 F 37 .7 33 .2 34 .0 23 .5 N 43 .1 46 .1 59 .1 75 .3 Insects
A 19 .2 20 .7 6 .9 1 .2 F 31 .1 56 .8 47 .9 N 68 .9 35 .4 37 .6
B ells of church
A 0 .0 7 .8 14 .5 F 44 .2 48 .8 57 .3 88 .0 N 38 .3 28 .8 27 .2 12 .0 M usic played
on street A 17 .5 22 .4 15 .5 0 F 2 .3 7 .0 32 .2 23 .5 44.6 17 .9 18 .0 18 .5 15 .3 N 77 .8 77 .6 17 .0 69 .8 47.2 68 .3 69 .3 80 .5 84 .7 Surrounding
speech A 19 .9 15 .4 50 .8 6 .7 8 .2 13 .8 12 .7 1 .0 0 F 20 .3 25 .5 54 .1 29 .5 27 .4 11 .7 6 .9 1 .7 1 .0 N 54 .3 50 .8 19 .9 53 .0 53 .4 48 .4 40 .3 69 .0 54 .8 C hildren 's
shouting A 25 .4 23 .7 26 .0 17 .5 19 .2 39 .9 52 .8 29 .3 44 .2 F 5 .5 8 .0 8 .6 12 .9 7 .1 N 89 .9 84 .7 62 .0 58 .4 17 .9 Pedestrian
crossing A 4 .6 7 .3 29 .4 28 .7 75 .0 F 0 .6 3 .5 31 .3 2 .7 1 .6 2 .4 1 .0 N 26 .0 53 .0 16 .6 59 .8 35.4 38 .7 43 .6 Passenger
cars A 73 .4 43 .5 52 .1 37 .5 63.0 58 .9 55 .4 F 3 .4 1 .3 1 .6 3 .7 2 .1 N 52 .3 84 .3 39.2 38 .9 37 .9 Passenger
buses A 44 .3 14 .4 59.2 57 .4 60 .0 F 2 .9 1 .0 1 .4 2 .0 N 32 .2 35 .3 57 .9 54 .7 V ehicle
parking A 64 .9 63 .7 40 .7 43 .3 C onstruction F 2 .1 32 .5 2 .2 2 .1
N 52 .9 11 .5 18 .0 19 .2 A 45 .0 56 .0 79 .8 78 .7
Significant difference exists for some sounds among the cities, likely caused by cultural factors.
Classifications for various sounds in urban open public spaces (%).
People’s noise sensitivity may differ considerably in different citiesKassel has the quietest home environment, whereas Alimos has the noisiest. With similar Leq, the evaluation score in Kassel is much higher than in Alimos. • People from a noisy home environment adapt more to noisy urban spaces? • Cultural difference - people in Germany are more aware of urban noises?
in residential buildingsTaipei/Beijing people prefer
music from outside but Sheffield people not
A related study
Semantic differential analysisSemantic differential analysisThe technique, developed by Osgood et al in
order to identify emotional meaning of words, has been extended to a large variety of concepts
•• A soundscape walk in A soundscape walk in four typical open urban four typical open urban public spaces in public spaces in SheffieldSheffield
•• Comparison between Comparison between general public and general public and architectural studentsarchitectural students
•• Comparison between Comparison between Beijing and SheffieldBeijing and Sheffield
Very Fairly Little Neutral Little Fairly Very *Discomfort -3 -2 -1 0 1 2 3 Comfort *Noisy -3 -2 -1 0 1 2 3 Quiet *Unpleasant -3 -2 -1 0 1 2 3 Pleasant Ugly -3 -2 -1 0 1 2 3 Beautiful *Boring -3 -2 -1 0 1 2 3 Interesting *Artificial -3 -2 -1 0 1 2 3 Natural Unfriendly -3 -2 -1 0 1 2 3 Friendly *Dislike -3 -2 -1 0 1 2 3 Like *Harsh -3 -2 -1 0 1 2 3 Gentle Pure -3 -2 -1 0 1 2 3 Impure *Soft -3 -2 -1 0 1 2 3 Hard Sad -3 -2 -1 0 1 2 3 Happy *Slow -3 -2 -1 0 1 2 3 Fast Dark -3 -2 -1 0 1 2 3 Bright Low -3 -2 -1 0 1 2 3 High *Flat -3 -2 -1 0 1 2 3 Sharp Heavy -3 -2 -1 0 1 2 3 Light *Everywhere -3 -2 -1 0 1 2 3 Directional *Simple -3 -2 -1 0 1 2 3 Varied *Deadly -3 -2 -1 0 1 2 3 Echoed *Close -3 -2 -1 0 1 2 3 Far Unsafe -3 -2 -1 0 1 2 3 Safe *Unsocial -3 -2 -1 0 1 2 3 Social *Meaningless -3 -2 -1 0 1 2 3 Meaningful Weak -3 -2 -1 0 1 2 3 Strong Unsteady -3 -2 -1 0 1 2 3 Steady *Calming -3 -2 -1 0 1 2 3 Agitating *Smooth -3 -2 -1 0 1 2 3 Rough
Indices used in the evaluationconnotative and denotative meaningsconnotative and denotative meanings
Identify the main factors that characterize the soundscapeIdentify the main factors that characterize the soundscape
FACTORS INDICES 1 2 3 4 Comfort-discomfort .701 .164 .138 Quiet-noisy .774 Pleasant-unpleasant .784 .258 .157 Interesting-boring .435 .272 .274 .103 Natural-artificial .532 .102 .240 Like-dislike .519 .575 .247 .151 Gentle-harsh .502 .531 .123 Hard-soft .812 Fast-slow .827 Sharp-flat .220 .345 .488 Directional-everywhere .234 .441 .267 Varied-simple .115 .674 .167 Echoed-deadly .204 .531 Far-close .550 Social-unsocial .672 .462 Meaningful-meaningless .126 .585 .469 Calming-agitating -.143 .708 .286 Smooth-rough .683 .396
Factor analysis of the soundscape evaluation in Barkers Pool and the Peace Gardens in winter and spring. Kaiser-Meyer-Olkin measure of sampling adequacy, 0.798; cumulative%, 52.77; extraction method, principal component analysis; rotation method, varimax with Kaiser normalization; N=491.
Factor 1 (26%) Factor 1 (26%) –– relaxationrelaxationcomfortcomfort--discomfort, quietdiscomfort, quiet--noisy, pleasantnoisy, pleasant--unpleasant, naturalunpleasant, natural--artificial, likeartificial, like--dislike and gentledislike and gentle--harshharsh
Factor 2 (12%) Factor 2 (12%) –– communicationcommunicationsocialsocial--unsocial, meaningfulunsocial, meaningful--meaningless, calmingmeaningless, calming--agitating and roughagitating and rough--smoothsmoothFactor 3 (8%) Factor 3 (8%) –– spatialityspatialityvariedvaried--simple, echoedsimple, echoed--deadly and fardeadly and far--closecloseFactor 4 (7%) Factor 4 (7%) –– dynamicsdynamicsfastfast--slow and hardslow and hard--softsoft
The situation is more complicated than that for product soThe situation is more complicated than that for product sound quality, but still possible to identify major factors.und quality, but still possible to identify major factors.
Part IIPart II
SOUNDSCAPE DESIGNSOUNDSCAPE DESIGN
System
SoundsSounds
SpaceSpace
PeoplePeople
EnvironmentEnvironment
ToolsTools
Measurement/monitoring
Evaluation index
A systematic approach towards intentionally planning and designing
Soundscape description: Soundscape description: factors to be consideredfactors to be considered
system
Each source (type)
Sound pressure level
Spectrum
Psychological/social characteristics
Source movement
Location
Variation (hour, day, season)
Duration
Impulsive characteristics
Meaning
Natural or artificial sound
Relation to activities
Soundmark Effect of the space
Reverberation
Reflection pattern and/or echogram
General background sound
Sounds around the space
Users Acoustic condition at users’ home and work, experience, etc
Social/demographic factors, activities and behaviours
Other environments Temperature, humidity, lighting, etc
Visual, landscape and architectural characteristics
Descriptive or holistic
Temporal conditions
Soundscape design: activities and sound elementsSoundscape design: activities and sound elements
In addition to dividing sounds as keynotes, foreground sounds anIn addition to dividing sounds as keynotes, foreground sounds and d soundmarkssoundmarks, sound sources in an urban open space can be divided into: , sound sources in an urban open space can be divided into:
active sounds: active sounds: relate to sounds from the activities in the space, relate to sounds from the activities in the space, e.g. group dancinge.g. group dancing
passive sounds:passive sounds: relate to the sounds from the landscape elements, e.g. relate to the sounds from the landscape elements, e.g. fountainsfountains
Spectrum Spectrum –– also important when using also important when using psychoacoustic magnitudespsychoacoustic magnitudesdynamic processdynamic processacoustic zones and scaleacoustic zones and scale -- suitable aural space suitable aural space or sourceor source--listener distance for each zonelistener distance for each zone… …
An urban open space can be designed to An urban open space can be designed to encourage activities generating active sounds.encourage activities generating active sounds.
sounds
Designable factors/potentials
ActiveActive sound: musicsound: music
People are not only interested in the music itself, but are alsoPeople are not only interested in the music itself, but are also attracted by the attracted by the activitiesactivities of the players. In this case, the type of music (e.g. classicalof the players. In this case, the type of music (e.g. classical music or music or pop music) is not a very important issue. pop music) is not a very important issue.
However, when music is played using loudspeakers, the type of muHowever, when music is played using loudspeakers, the type of music as well as sic as well as the sound level needs to be considered carefully. the sound level needs to be considered carefully.
Most people donMost people don’’t like loud music played from loudspeakers, whatever the music tt like loud music played from loudspeakers, whatever the music typeype. .
Spectrum analysisSpectrum analysis dynamic processdynamic process
Acoustic zones
PassivePassive soundsound: water: waterEndless effects in colouring the soundscape – ‘primary soundscape quality’
Landscape theory: ‘primary landscape qualities’ - water and foliage
Spectrum: most water sounds have significant high frequency components around 2k to 8kHz and some of them also have notable low frequency components.
making water sound distinctive from the backgroundDynamicDynamic: The flow rate of a water feature should not be constant. : The flow rate of a water feature should not be constant.
Cascade with Temple Pavilion in the Chatsworth Garden
50
55
60
65
70
75
80
16 31.5 63 125 250 500 1k 2k 4k 8k 16kFrequency (hz)
SPL
(dB
)
1 step 2 steps5 steps 7 steps
Examples showing design potentials:high frequency components come from the water splash itself, whereas when a large flow of water is raised to a very high level and then dropped to a water body or hard surface, notable low frequency components can be generated
Sound field simulation and parameter studiesSound field simulation and parameter studies
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-45
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-35
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-20
-15
-10
0 20 40 60 80 100 120
Source-receiver dis tance (m)
SPL
(dB)
25x25, diffuse25x25, geometrical50x50, diffuse50x50, geometrical100x100, diffuse100x100, geometrical
-50
-45
-40
-35
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-25
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-10
0 20 40 60 80 100 120
Source-receiver distance (m)
SPL
(dB
) 50206
-50
-45
-40
-35
-30
-25
-20
-15
-10
0 20 40 60 80 100 120
Source-receiver distance (m)
SPL
(dB
)
50x50, diffuse100x25, diffuse50x50, geometrical100x25, geometrical
-50
-45
-40
-35
-30
-25
-20
-15
-10
0 20 40 60 80 100 120
Source-receiver distance (m)
SPL
(dB
)
0.1, diffuse0.3, diffuse0.5, diffuse0.7, diffuse0.9, diffuse0.1, geometrical0.3, geometrical0.5, geometrical0.7, geometrical0.9, geometrical
SizeSize
ShapeShape AbsorptionAbsorption
HeightHeight
BoundaryBoundary
space
Based on several models [Future Computational Acoustics Workshop]
Case studiesCase studiesFurther showing design potentialsFurther showing design potentials
Preconceptions:Preconceptions: Respondents predicted the concrete barrier to be the most effecRespondents predicted the concrete barrier to be the most effective, tive, although the transparent barriers and deciduous vegetation barrialthough the transparent barriers and deciduous vegetation barriers judged most ers judged most aesthetically pleasing aesthetically pleasing These preconceptions were reflected in the results of the furtheThese preconceptions were reflected in the results of the further perception exercise, r perception exercise,
virtual reality environment RAVEvirtual reality environment RAVEfive barrier: concrete, metal, timber, transparent acrylic, and aive barrier: concrete, metal, timber, transparent acrylic, and a hedgerow of deciduous vegetationhedgerow of deciduous vegetation
peoplesocial and demographic factors, including age, gender, education, profession, residential status (i.e. local and non-local), cultural background, and acoustic environment at home and at working place; activities including moving type such as walking, playing with children, and sport; and non-moving type such as sitting, standing, reading, and watching;behaviours such as wearing earphone and sunglasses. The results have clearly demonstrated the importance and potential in considering the characteristics of the users.
Preconceptions, aesthetics: Preconceptions, aesthetics: barrier as examplebarrier as example
Landscape and acoustic satisfaction
Visual and acoustic satisfaction
Beijing
Taipei
SheffieldCorrelation between quiet and view when
choosing a living environment(Beijing data)
EU data
Consider auralConsider aural--visual interactionsvisual interactions
Environment if a place is very hot or very cold, perhaps none cares about soundscape…
Process of ANN learningProcess of ANN learning
• Important to develop a model to predict the subjective evaluation of soundscape quality at the design stage, using known design conditions.
• Given the complicated relationships between various factors, ANN is suitable• Initial modelling results suggest that there is a good convergence
Neural Network Analysis of SoundscapeNeural Network Analysis of Soundscape
Biological neural netBiological neural net
Soundscapeevaluation
Other physical comfort
Social/demographic
Foregroundsounds
ThermalOther physical comfort
Visual
Lighting
Physical parameters relating to thermal
Social/demographic
Thermal
Foreground sound
Background sound
Activities
behaviours
Social/demographic
Acoustic space
Source characteristics
tools
To aid urban soundscape design and for public To aid urban soundscape design and for public participation, it would be useful to present the 3D participation, it would be useful to present the 3D visual environment with an acoustic animation toolvisual environment with an acoustic animation tool
Multiple sourcesMultiple sourcesSource and receiver all movingSource and receiver all movingCalculation speed fastCalculation speed fastCalculation accuracy less criticalCalculation accuracy less critical
ProgressProgressConsiderable simplifications can be made in terms of algorithms Considerable simplifications can be made in terms of algorithms for urban spacesfor urban spacesFurther simplification possible in terms of subjective evaluatioFurther simplification possible in terms of subjective evaluation, depending on source typesn, depending on source typesA fast algorithms CRR has been developed, especially for SPLA fast algorithms CRR has been developed, especially for SPLAuralization techniques are explored with various levels of accuAuralization techniques are explored with various levels of accuracyracy((HRTF for spatial sound with headphone or using RAVE)HRTF for spatial sound with headphone or using RAVE)
Acoustic animation and auralisationAcoustic animation and auralisation
Design guidelinesDesign guidelines
Concluding remarksConcluding remarks
Importance of interdisciplinary approachImportance of interdisciplinary approachImportance of introducing Importance of introducing ‘‘scientificscientific’’ methods into soundscape research/designmethods into soundscape research/design
Great potentials of planning/designing soundscape has been demonGreat potentials of planning/designing soundscape has been demonstrated.strated.A systematic approach towards intentionally planning and designiA systematic approach towards intentionally planning and designing ng soundscape will greatly benefit practice and policessoundscape will greatly benefit practice and polices ……
Policy and regulations needed for urban open public spacesPolicy and regulations needed for urban open public spaces
Looking forward to other talks today Looking forward to other talks today …….. ..
Space
Presentation design tools Evaluation Prediction
Practice
Policies
PeopleSounds EnvironmentDescription Framework
Research
Practice and potentials
Many other issues and other kind of spaces/soundscapes
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