Ch 12- Sound Radiation And Sound Level

Question 0

Ultrasound

Answer 0

Air vibrations about 20k Hz

Question 1

Infrasound

Answer 1

Air vibrations below 20Hz

Question 2

Free vibrators

Answer 2

Vibratory is set into oscillation

Question 3

Driven vibrators

Answer 3

Kept vibrating by a continuously applied driving force.

Question 4

Free vibrators give rise to ___

Answer 4

Transient sounds

Question 5

driven vibrators give rise to ____

Answer 5

Fairly steady sounds which are aprx. constant in Amp and Freq.

Question 6

Human speech mechanism is an example of

Answer 6

Driven vibrator

Question 7

Radiation

Answer 7

The process of “giving off” energy

Question 8

A relatively larger radiating surface is required to

Answer 8

Radiate low frequency (long wavelength) sound efficiently

Question 9

Radiators do not radiate high frequency sound _____

Answer 9

Uniformly in all directions.

Question 10

The low frequencies are radiated ______ around a loudspeaker because of _______.

Answer 10

Fairly uniformly, diffraction

Question 11

Sound intensity level SIL

Answer 11

=10log(I/I ref)

Question 12

Sound pressure level SPL

Answer 12

20log(P/P ref)

Question 13

Sound level meter

Answer 13

A device used to measure sound pressure levels