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100

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120

20 30 40 50 60 70 80 90 100

LW

A[d

B]

Speed [km/h]

R7

ASJ:GEV

LW=46.9 +30logV

LW=48.5 +28.6logV

LWA determination of passenger car

Measurement site ：R7

S A K A M O T O L A B . [Measurement and Evaluation of

Sound Environment in Urban City ] Advanced Mobility Research Center

Environmental Acoust ic Engineer ing

http://www.acoust . i i s .u -tokyo.ac. jp Department of Architecture, Graduate school of Engineer ing

Measurement and Evaluat ion of Sound Environment in Urban City Acoust ic laboratory（Ce-101, Ce-B01）

Welcome to aural demonstration using sound

field simulator!

Measurement and Evaluation of Sound Environment in Urban City

Our laboratory treats various acoustical issues about measurement and evaluation of sound environment in urban city. Evaluation methods of acoustical environment and techniques of control and prediction of sound will be introduced. ◆Development of prediction methods：Numerical analysis ◆Room acoustic design：Auditorium, Music practice room, Open-type classrooms ◆Acoustic measurement：Sound propagation, Sound insulation and absorption ◆Development of sound field simulation：6 channel recording-reproduction system ◆Subjective evaluation：Concert halls, Living environments, Public spaces, Offices, Healthcare facilities, other small spaces such as a car cabin

Sound environment of railway station Measurement of acoustic properties by using a parametric loudspeaker

A parametric loudspeaker, which has super sharp directivity, is expected to enable in-situ measurement of acoustic properties of materials without extraneous diffraction from sample edge or obstructive reflections from room boundaries. Basic examination on the measurement method is being studied experimentally.

Subjective evaluation of noise with tonal components

Tonal components in environmental noise may increase the annoyance to the noise. Auditory experiments are conducted to know how the frequency characteristics affect the subjective perception such as loudness and annoyance.

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67

69

71

73

75

77

79

-10 -5 0 5 10 15 20

M40

LL

(M)

[phon]

Tonal Audibility [dB]

40 Hz

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67

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77

79

-10 -5 0 5 10 15 20

M200

LL

(M) [p

hon]

Tonal Audibility [dB]

200 Hz

⬜︎ Standard stimuli ● Comparison stimuli

Results of loudness matching test. (back ground noise : -4 oct /dB)

In a railway station, an appropriate announcement is very important for users’ convenience and safety. A field survey and a subjective experiment were conducted. By using a 3D sound field simulation system, listening difficulty and loudness of the announcement were evaluated.

Subjective evaluation by using 3D sound field simulation system

Field measurement

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2

3

4

5

-5 0 5 10 15 20

データ 1 14:04:39 平成 30/03/29

新宿

品川

東京

大宮

上野

S/N

● UN ST.× OM ST.▲ TK ST.□ SN ST.◆ SJ ST.

-5 0 5 10 15 20SNR [dB]

List

enin

g d

iffi

cult

y

5. Extremely

4. Very

3. Moderately

2. Slightly

1. Not at all

Relationships between listening difficulty and SNR

Parametric loudspeaker

Free field measurement

In-situ measurement

Development of prediction method of road traffic noise

Road traffic noise is one of the most important issues for environmental assessment and accurate prediction method is essential for appropriate maintenance of living environment. Such a prediction method has been developed from viewpoints of sound emission and propagation.

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65

0 1 2 3 4 5 6

Par

amet

er a

[dB

]

L M GEV HVLV

Vehicle class

LWA = a +30log10Vn 11

n 15n 18 n 15 n 16