ACOUSTIC WEEK -10: Acoustic Design

Acoustic Design

Sound trajectory in the auditorium

Sound trajectory in the auditorium

- The difference in the distance in the same sound speed will cause a time difference

- The time difference is related to the sound level

Ceiling

• The height of the ceiling is related to the reverberation time

H – 20T

H = ceiling height (ft)

T = reverberation time (mid-frequency)

~

Concert hall

To get a long reverberation:

• High ceilings

• The entire room must be a sound reflector

Echo

• Repeating a clear sound of the original sound Echo control can be done by:

• Space form

• Efficient sound-absorbing material

Sound absorbent

Back wall design to control echo

Back wall design to control echo

Back wall design to control echo

Back wall design to control echo

Sidewall design for echo control

To control the horizontal sound direction

• Fan shape

• Rectangular shape

• Stepped shape

• Reverse fan shape

Sidewall design for echo control

• Fan Shape

Sidewall design for echo control

• Rectangular Shape

Sidewall design for echo control

• Stepped Shape

Sidewall design for echo control

• Reverse Fan Shape

Articulation index

• Subjective measurement of the

intelligibility of the source of speech

(Flutter echo)

repeated interreflection

of sound energy between

parallel opposite, concave

surfaces

Concave surface

Focused Sound

Concave surface

creep

The basic form

of the theater

stage

balcony

Flexible Room Volume

Flexible Room Volume

end