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Front 1

Sound Wave

Back 1

longitudinal pressure wave in air or an elastic medium especially one producing an audible sensation

Front 2

Acoustics

Back 2

the science that studies the waves that are conducted through matter due to the motion of the matter

Front 3

Architectural Acoustics

Back 3

the study of acoustics when the air is contained in a room

Front 4

frequency

Back 4

the rate at which the source produces sound waves ; the number of times per second that a vibrating body completes one cycle of motion.

Front 5

hertz , 1Hz= 1 cps (cycle per second )

Back 5

unit for frequency

Front 6

true

Back 6

True or False: bass sounds have low frequencies

Front 7

false

Back 7

True or False: treble sounds have low frequencies

Front 8

20-20,000 Hz

Back 8

a healthy , young person can hear sounds with frequencies from roughly _________.

Front 9

300-3000 Hz

Back 9

The sound of human speech is mainly in the range ______.

Front 10

Architectural Acoustics

Back 10

the effect of building design on the control of sound in buildings

Front 11

Engineer

Back 11

Responsibilities: Keep the sound from mechanical equipment at an acceptable level

Front 12

Manufacturer

Back 12

Responsibilities: designing machinery for quiet operation

Front 13

Architectural Consultant

Back 13

Responsibilities: Can point out possible solutions to provide satisfactory noise control

Front 14

Architect

Back 14

Responsibilities: recognize a potential noise problem in a proposed building & take steps to solve it

Front 15

Sound

Back 15

produced by vibrating objects & reaches the listener's ears as waves in the air or other media

Front 16

Sound level

Back 16

the measure of the strength of sound

Front 17

decibels (dB)

Back 17

unit of Sound level

Front 18

true

Back 18

true or false: the shorter the wavelength, the higher the frequency, & the higher the pitch

Front 19

decibel (dB)

Back 19

a logarithmic scale applicable to any parameter

Front 20

Pa (Pascals)

Back 20

the amplitude of pressure is measured in ____.

Front 21

20 micro Pa (2x10^-5) to 20 Pa

Back 21

Range of acoustic pressures

Front 22

0-140dB

Back 22

Manageable logarithmic scale

Front 23

85 dB

Back 23

Government research suggests the safe exposure limit is ___ for 8 hours a day

Front 24

Sound intensity

Back 24

the rate of sound energy transmitted in a specified direction per unit area normal to the direction

Front 25

0.00002 Pa

Back 25

0 dB is equivalent to sound pressure level (Lp) of ____

Front 26

Sound Power

Back 26

the sound energy transferred per second from the noise source to the air

Front 27

0.1 µW or 0.0000001 Watts

Back 27

An average whisper generates a sound power of _____.

Front 28

Sound power level,Lw

Back 28

Often indicated in the machinery to indicate the total sound energy radiated per second

Front 29

loudness

Back 29

the human impression of the strength of a sound

Front 30

Masking

Back 30

the process by which the audibility of one sound is reduced due to the presence of another at a close frequency

Front 31

reverberation

Back 31

the prolongation of the sound in the room caused by continued multiple reflections

Front 32

Reverberation time

Back 32

time taken for sound energy to decay in a room by a factor of 1-million (by 60 dB )

Front 33

true

Back 33

True/ False: domes & concave surfaces cause reflections to be focused rather than dispersed which can cause annoying sound reflections

Front 34

phon

Back 34

unit of loudness level

Front 35

flutter

Back 35

rapid succession of echoes caused by the reflection of sound waves back & forth between two parallel surfaces

Front 36

Noise Reduction Coefficient (NRC)

Back 36

A single-number index for rating how absorptive a particular material is

Front 37

STC ( Sound Transmission class )

Back 37

a single-number rating of a Material's or assembly's barrier effect

Front 38

sound insulation

Back 38

required to eliminate the sound path from a source to a receiver

Front 39

sound absorption

Back 39

Occurs when some/all of the incident sound energy is either converted into heat/ passes through the absorber

Front 40

diffusion

Back 40

scattering or random redistribution of a sound wave from a surface

Front 41

diffusion

Back 41

Which is extremely important for rooms used for musical performances :

a) Reflection

b) diffusion

c) diffraction

Front 42

diffraction

Back 42

bending/ flowing of a sound wave around an object or through an opening

Front 43

Concave Reflector

Back 43

focus sound, causing hot spots & echoes in the audience seating area

Front 44

Flat Reflector

Back 44

flat-hard surfaced building elements (large enough & oriented properly) that is tilted slightly; effectively distribute reflected sound.

Front 45

large convex, hard-surfaced building elements

Back 45

most effective sound-distributing forms

Front 46

Convex Reflector

Back 46

more evenly distributed reflected sound across a wide range of frequencies; most effective sound-distributing forms; reflected sound energy from this surface diverges, enhances diffusion , desirable for music.