sound + acoustics

Question 1

Case - School of Music, University of Illinois

Answer 1

Haary Wiese and Associates, 1969
Shape/volume - orchestral arrangement cone shape
Angles of walls and ceiling reflect sound towards other performers/conductor , first order reflections must occur quickly (otherwise an echo or bounce is created)

Large amounts of sound are diffused and
absorbed by the back wall - checkerboard patterning with soft material/insulation between

Question 2

Environment shapes sound with two main qualities

Answer 2

Geometry and materiality

Question 3

Propagation of sound
(4)

Answer 3

Transmission
Absorption
Reflection
Diffusion

Question 4

Sounds definition

Answer 4

Energy - waves caused by vibrations / pressure changes as sound waves

Travel through materials

Question 5

Frequency

Answer 5

How many waves per second

Measured in Hertz

Defines pitch

Question 6

Amplitude

Answer 6

The size of a waves displacement

Volume/ intensity

Measured in decibels / dB

Question 7

Wavelength

Answer 7

Distance between two matching pts on a sound wave - shorter = higher frequency/pitch

Question 8

Scores for sound control

Answer 8

Sound transmission class (STC)

Higher number - better blocking of transmission

Noice reduction coefficient (NRC)
Higher no. (closer to 1) =greater absorption

Question 9

Sound Pressure Levels (SPL)

Answer 9

Pascals (Pa)

Question 10

Psychoacoustics

Answer 10

Loudness
Pitch
Timbre
Spatial hearing
Masking

Question 11

Sound goals (3) in design

Answer 11

Clarity
Comfort
Control

Question 12

Zoning + spatial layout

Answer 12

Noisy + quiet apart
Buffer zones
Thoughtful noise source placement
Logical room arrangement

Question 13

Cases

Answer 13

Houtan Park, Shanghai - wetlands + earthwork to absorb urban sound

The Shard, London
Heavily zoned - separated by floors
Residential spaces - above urban/commercial zones

Double-layered facades - air gap (acoustic and thermal insulation

Question 14

Material properties that influence sound behaviours

Answer 14

Absorb
Reduce echo/noise
Foam (polyurethane) fabrics/fibres, carpet, fibreglass

ABSORPTION COEFFICIENT (0-1)

Reflect
Polished, smooth surfaces, glass, concrete

Isolate / block
Dense materials, drywall, mass-loaded vinyl (MVL)

Diffuse
Reduces echoing, lattices/slat, textured concrete

Attenuate
Decreases loudness - transmission - insulated walls have high attenuation