7.1.1_Acoustics Vocab

Question 1

compression/expansion cycles per second

Answer 1

frequency

Question 2

measured in hz

Answer 2

frequency

Question 3

distance between similar points, on successive waves.

Answer 3

wavelength

Question 4

velocity depends on:

Answer 4

medium and temp of medium

Question 5

the order of sounds on a frequency related scale

Answer 5

pitch

Question 6

measure of sonic energy per time

Answer 6

sound power

Question 7

sound power per unit area

Answer 7

sound intensity

Question 8

measure of amount of sound,
generated by a source,
independent of its environment.

Answer 8

Sound Power Level (PWL)

Question 9

watts per square meter,

intensity of sound at a given location

Answer 9

Sound Intensity Level (IL)

Question 10

sound pressure exerted
by sound wave on a surface
at a given location,
varies w/ barometric pressure.

Answer 10

Sound Pressure Level (SPL)

Question 11

maximum SPL in given location,

using standardized reference contours.

Answer 11

Noise Criteria Curves

Question 12

modification of NC curves,

that have SPL’s lower than NC curves

Answer 12

Preferred Noise Criteria (PNC)

Question 13

a measure of speech intelligibility,

* all components of system working together

Answer 13

Articulation Index (AI)

Question 14

rating component performance,

* does NOT account for masking sound.

Answer 14

Articulation Class (AC)

Question 15

Purpose: simplify rating room construction / finish matl’s

Answer 15

Noise Reduction Coefficient (NRC)

Question 16

arithmetic dif. in dB,
between IL in two rooms,
separated by barrier for TL.

Answer 16

Noise Reduction (NR):

Question 17

STC 25

Answer 17

normal speech understood easily through wall

Question 18

STC 40

Answer 18

onset of “privacy”

Question 19

STC 50

Answer 19

loud stereo faintly heard, 99% of population not annoyed

Question 20

STC 60

Answer 20

superior

Question 21

reduction of sound energy levels

through use of material

Answer 21

Insulation:

Sound Insulation:

Question 22

minimizing sound transmission

through building design.

Answer 22

Isolation:

Sound Isolation:

Question 23

absorption coefficient in room should be:

Answer 23

.20 – .50

Question 24

material w/ coefficient < 0.2 is

Answer 24

reflective

Question 25

material w/ coefficient > 0.2 is

Answer 25

absorptive

Question 26

each doubling of absorption in room reduces reverberation by

Answer 26

50%

Question 27

concert hall reverberation

Answer 27

2 sec

Question 28

lecture hall reverberation

Answer 28

1 sec