Deck 4: Audio Physics

Question 1

The Potential Acoustic Gain Formula states that as the listeners double their distance from the sound source, the sound pressure level they perceive will decrease by 6dB.

Answer 1

True

Question 2

The inverse square law:  states that all radiation patterns will decrease by the square of the distance.

Answer 2

True

Question 3

A sound level meter measures the sound pressure level of a source.

Answer 3

True

Question 4

The frequency response of an audio amplifier will typically be _________.

A) 20-20KHz
B) 10-10KHz
C) 20K-200KHz
D) 10K-100KHz

Question 5

A sound wave cannot exist at various different frequencies.

Question 6

The velocity of sound decreases at temperature increases.

Question 7

Any two sounds whose frequencies make a 2:1 ratio are said to be separated by an octave.

Question 8

The human ear detects all frequencies equally.

Question 9

The regions of high pressure in a sound wave are called _______.

A) rarefactions
B) compressions
C) intensity
D) sound pressure level

Question 10

Dynamic range represents the maximum span between the loudest and softest level of sound.

Question 11

Coherence represents a(n) _________ relationship between two signals.

A) In phase
B) Out of phase
C) Delayed
D) Equal amplitude

Question 12

0dB represents a complete absence of sound.

Question 13

What type of generator generates equal intensities of all frequencies in the range of 20 to 20,000 Hz?

A) Signal
B) Audio
C) Pink noise
D) White noise

Question 14

A sound wave is an example of a ____________wave.

A) vacuum
B) electromagnetic
C) electrostatic
D) mechanical

Question 15

The inverse square law:  states that by decreasing the distance to the source by half, will increase the sound intensity by 6db.

Question 16

The threshold of hearing is set to 0dB.

Question 17

A doubling of acoustic power produces _________.

A) Doubling of voltage
B) Doubling of decibels
C) 3dB increase
D) 6dB increase

Question 18

The inverse square law:  will work of only sound waves.

Question 19

Low frequencies are direct line of sight.

Question 20

The inverse square law:  states that the measured level of signal intensity will decrease by 3 dB for every doubling of distance from the source.

Question 21

For question #24, calculate the signal level, in decibels, at 7m.

Question 22

The signal attenuation for a coaxial cable transmitting 1MHz is listed as 1.3dB per 100m. How much loss will be seen at 700m?

Question 23

Calculate the power gain, in decibels, when increasing from 100W to 400W.

Question 24

The velocity of sound in air is equal to 1,130ft/s. Calculate the wavelength of a 2KHz signal.

Question 25

150Hz represents the lower frequency range, 8KHz represents the upper frequency range. Calculate the bandwidth of the device.

Question 26

Calculate the voltage loss, in decibels, for a load measuring 18V and a source measuring 24V.

Question 27

Calculate the 5^th octave of a 200Hz tone.

Question 28

A signal source measures 90dB at 1m. Calculate the decibel loss at 7m.

Question 29

5W referenced to 1mW is equal to _______ decibels.

Question 30

Calculate the 5^th harmonic of a 200Hz tone.