Hearing Science Practice Questions

a jet airplane takes 2 hours to travel 1600 miles in a straight line. what is the avg velocity of the jet?

800 mph

a grandfather clock ticks once when the pendulum swings from left to right and once again on the swing from right to left. there are two ticks each second. what is the frequency of pendulum motion in cycles per second (Hz)?

1 Hz

when a wave travels from one place to another, what is transported?

energy

assume that you have a periodic wave traveling down an infinitely long rope. what happens to the wavelength if you increase the period of this wave?

it increases

if the fundamental frequency of a rope fixed at both ends is 30 Hz, the frequency of the second harmonic is

60 Hz

A long pendulum hanging from the classroom’s ceiling has a period of 8s. what is the frequency of this pendulum?

1/8 Hz

a node is the point of maximum displacement on a standing wave

false

standing waves…

c. are a result of the superposition of two traveling waves

while standing on a dock, you observe waves passing beneath you. if you observe 20 wave crests passing directly below you in 2 minutes and judge the crests to be 1m apart, what’s the period of the waves?

6 seconds

a pure tone is always…

a sinusoidal sound wave

sometimes, you can faintly hear somebody speaking behind a wall in the room next to you because…

part of the original sound wave is transmitted through the wall

in transverse waves, particles of the medium move perpendicular to the direction in which the wave travels

true

compliance is inversely proportional to stiffness

true

the amount of inertia of an object is directly proportional to…

mass

in the following figure of a pendulum, the inertial force is maxium at

A

force =

mass x acceleration

if a hockey puck slides on a perfectly frictionless surface, it will eventually slow down because of its inertia

false

the unit for pressure is N/m²

true

sawtooth waves have energy at all harmonics (even and odd)

true

3rd harmonic =

2nd overtone

as frequency increases,

A and C

the frequency of free vibration is also called resonant or natural frequency

true

mass reactance is greater at higher frequencies

true

stiffness reactance is greater at low frequencies

true

at resonant frequency…

B and C

air and water have the same impedance

false

the rate at which work is done is called…

power

which statement(s) are true?

A and B

a band pass filter has __ cutoff frequencies

2

a very small portion of energy is transmitted if there is an impedance mismatch

true

a filter which is used to eliminate just one frequency is called…

notch filter

which type of filters have two cutoff frequencies?

A and B

which statement is true for a tube open at both ends?

an antinode will form at both ends

an organ pipe is 1m long and is open at one end and closed at the other. which of the following is the frequency of one of the harmonics of the pipe? assume that the speed of sound is 340 m/s

255 Hz

in a tube only open at one end…

only odd harmonics can be produced

tube length and fundamental frequency are inversely proportional to each other

true

three pure tone frequencies of 6 Hz, 4 Hz, and 3 Zz are played at one time near a taut string of length 1m that is tied at both ends. it is observed that only the 6 Hz tone makes the string vibrate in one of its allowed modes. from this info, you can deduce that…

the lowest natural resonant frequency is 6 Hz

A tube open at both ends can resonate at odd and even harmonics

true

you set up a standing wave on a string, as shown. what harmonic is this?

3rd

you set up a standing wave on a string, as shown. how many nodes are there?

4

which of these statements is true?

the decibel is the standard unit of measure of sound level

identify the correct statement

A and B

50 dB SPL = 50 dB IL

true

if there are two sound sources in a room, and each source generates 80 dB of noise, what is the overall intensity of noise in that room? 

83 dB

the unit of power is watt

true

identify the correct equation

intensity = power/area

according to the inverse square law, “the sound energy per unit area received at any point is _____ proportional to the square of the distance from the source”

A. inversely

8.2 bels = ____ decibels

82 dB

if there are 10 sound sources in a room, each source generates 70 dB of noise, what will be the overall intensity level of noise in that room?

80 dB

an increase in sound pressure by a factor of 2 corresponds to how many decibels?

6 dB

what is the sound pressure level of re: 2×10¹ Pa of a sound with an absolute pressure of 2×10^4?

60 dB

10 dB corresponds to what intensity ratio?

10

what is the intensity level re: 10^-12 watt/m² of a sound with an intensity of 2×10^-6 watt/m²?

63 dB

an increase in intensity by a factor of 4 corresponds to how many decibels?

6

an increase in intensity by a factor of 10 corresponds to how many decibels?

10