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AUDE 5140 - Acoustics > Final Exam Study Guide > Flashcards

Final Exam Study Guide Flashcards

1
Q

what happens when stiffness is increased

A

rate of vibration increases

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2
Q

what happens when mass is increased

A

rate of vibration decreases

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3
Q

What are the phases of a wave?

A

90 - peak (compression)
180 - on the line
270 - trough (rarefaction)
360 or 0

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4
Q

What happens when two sound waves are added together, when the sound waves have the same amplitude
both sound waves have the same frequency the two sound waves are 180o out of phase

A

the resulting wave will equal zero and this is called a cancellation interference.

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5
Q

what is represented on the x axis of a waveform

A

time

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6
Q

describe simple harmonic motion, starting and ending with equilibrium, and the forces and physical properties involved.

A

Object is at rest (equilibrium)
Object is set in motion by a force
It is displaced to a max displacement
It then returns back to equilibrium due to restoring force of elasticity
It is displaced again to a max displacement in the opposite direction (due to inertial forces)
The object returns back to equilibrium because of restoring forces of elasticity
This motion continues indefinitely until damping (friction) causes it to stop

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7
Q

Once a sound source has been generated, describe how sound energy travels from the source through air. Include what happens to sound over time in a natural sound environment.

A

Sound source is at rest (equilibrium)
Sound source is set into motion
this motion causes the air molecules next to it to begin vibrating
Those first set of air molecules then cause the next set of molecules beside them to begin to vibrate
This area where there is an increase in air pressure is called condensation
Each individual air molecule is moving in SHM in their own axis
The first set of air molecules then return back to their equilibrium and this area of low pressure is called rarefaction
Damping, due to friction, occurs over time in a natural sound environment causing this motion to stop.

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8
Q

has a tonal quality

A

periodic

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9
Q

comprised of freq that have no particular math relationship to each other

A

aperiodic

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10
Q

comprised of harmonics

A

periodic

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11
Q

single pure tone

A

periodic

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12
Q

If a sound has a sound pressure level of 0 dB SPL, what is the pressure of that sound in micropascals?

A

20

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13
Q

Imagine someone tells you that a sound is “35 dB”. Why is this incomplete information?

A

This is incomplete because we don’t know the full reference. For example, it could mean it is 35 dB SPL or it could be 35 dB IL.

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14
Q

What does the term rms amplitude refer to?

A

average amplitude

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15
Q

If a waveform has a period of .004 seconds, what is the frequency in Herz?

A

250

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16
Q

What are harmonics? What does it mean to say that sounds within a harmonic complex are harmonically related?

A

Harmonics are the individual components of a complex sound. They are whole number multiples of the fundamental frequency, meaning that they are harmonically related.

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17
Q

Imagine that you are reading a research paper with your clinical preceptor and the sound descriptions are all in dB IL (dB intensity level). Your clinic preceptor asks you which type of dB is greater, dB IL or dB SPL. How you do answer?

A

dB IL and dB SPL are equal to each other

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18
Q

What is the log of 100?

A

2

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19
Q

amount of change from equilibrium position

A

amplitude

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20
Q

refers to a point within the cycle of SHM

A

phase

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21
Q

number of full cycles of SHM within a period of time

A

frequency

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22
Q

accurately describe sound transmission through air

A

sound can be described as a disturbance or vibrations of the molecules of an elastic medium
air molecules that are in a sound wave’s path move in SHM
Sound propagation causes regions of high and low pressure that alternate over time

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23
Q

Combine two tones of the same frequency, that have the same amplitude and starting phase

A

resulting wave has double the amplitude with same phase

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24
Q

Combine two tones of the same frequency, that have the same amplitude, and are 180 degrees out of phase

A

two tones cancel each other out

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25
Q

Combine two tones of the same frequency, that differ in starting phase by something other than 0 degrees or 180 degrees

A

will have areas of increased and decreased amplitude throughout the cycle, period stays the same

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26
Q

Calculate dB IL for a sound intensity of 10-10 watt/m2

A

20

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27
Q

Going from 0 dB SPL to 20 dB SPL represents what amount of increase in pressure?

A

Ten times the pressure (ten-fold increase)

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28
Q

A constant-percentage bandwidth filter is what type of filter?

A

band pass filter

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29
Q

The attenuation rate or the rejection rate refers to what?

A

amount of change in dB per octave

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30
Q

something that changes the frequency composition of a sound or how sound changes when it passes through a system

A

filters/transfer function

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31
Q

high pass filter has

A

lower cutoff

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32
Q

low pass filter has

A

upper cutoff

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33
Q

band pass has

A

upper and lower cutoff = BW

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34
Q

allows all sound frequencies to pass except for a very brief frequency range.

A

band reject filter

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35
Q

Calculate dB SPL for a sound pressure of 200 micropascals.

A

20

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36
Q

what is clinical definition of threshold

A

50% or .5

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37
Q

Each point along the basilar membrane has a best or characteristic frequency, where the response is optimal to sounds of a specific frequency.

The response (output) of a healthy basilar membrane at the characteristic frequency to varying levels of sound input is (select one)

A

nonlinear/compressive

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38
Q

With regards to human hearing, the term dynamic range refers to:

A

The range between the least audible sound and the highest tolerable sound (90-120dB)

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39
Q

the least amount of amplitude of a stimulus detected

A

absolute threshold

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40
Q

least amount of noticeable change along a single dimension

A

difference threshold

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41
Q

Explain why cochlear nonlinearities are responsible for the low auditory thresholds seen in the typical and unimpaired human auditory system

A

It is because the outer hair cells amplify low level inputs that is how we get our very low auditory thresholds.

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42
Q

the range of input equals the range output

A

linear

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43
Q

NOT equal or the same

A

compressive/nonlinear/logarithmic

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44
Q

what is sensation leve

A

threshold minus presentation

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45
Q

If a patient’s hearing threshold is 45 dB HL and you present a tone at 60 dB HL, what is the dB SL of the tone?

A

15 dB SL

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46
Q

Your patient has a hearing threshold at 2000 Hz of 40 dB HL. You want to present a tone to them at the same frequency at 40 dB SL. At what presentation level are you presenting the tone for it to be 40 dB SL?

A

80 dB

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47
Q

Minimum detectable signal strength with a 50% response rate.

A

threshold

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48
Q

physical process the sensory receptors are detecting sensory stimuli (ABR)

A

sensation

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49
Q

psychological process, organization, interpretation and requires conscious experience of those sensations. (Hearing screening, behavioral threshold) you need a response

A

perception

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50
Q

the amount of change divided by the original stimulus.

A

weber’s fraction

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51
Q

Presented at 10 they noticed the difference at 20

A

10-20 =10 (you subtract the difference) 10/10=1

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52
Q

Presented at 1,000 and you notice a difference at 1,005

A

1,000-1,005= 5 5/1,000= 0.005

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53
Q

what is weber’s law

A

1st is that as your initial quantity gets larger you need a bigger difference to tell them apart. (so the Just noticeable difference differential sensitivity gets bigger/larger) 2nd is that the fraction should be the same throughout. Webers fraction should be a constant. Weber’s fraction is the amount of change divided by the original stimulus.

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54
Q

Test assesses the smallest detectable difference between two stimuli that vary in sound pressure.

A

difference sensitivity

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55
Q

Test assesses the least amount of sound pressure level at which a subject responds 50% of the time.

A

absolute sensitivity

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56
Q

What makes a psychoacoustic procedure adaptive?

A

Each successive presentation level is determined based on the patient/subject response

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57
Q

stimuli presented at random order, multiple trials per level

A

method of constant stimuli

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58
Q

patient controls the stimulus

A

method of adjustment

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59
Q

threshold estimated using descending and ascending runs with pre determined starting levels

A

method of limits

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60
Q

If we wanted to understand how much to increase a sound level for it to be perceived as double the original sound, what method would we chose?

A

direct scaling procedure

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61
Q

convert 60 dB HL to SPL at 2000 Hz using TDH 49/50 headphones

A

71

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62
Q

Your patient’s threshold is 25 dB HL. You present a tone at 65 dB HL at the same frequency. At what level in dB SL did you present the tone? Enter the number only.

A

40

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63
Q

According to our current understanding of measuring perceptual sensitivity, a subject or patient would never respond to a stimulus presented below their measured threshold of sensitivity for that sound.

A

false

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64
Q

What is dB level of a 2000 Hz tone perceived as having a loudness of 100 phons? (see chart)

A

95 dB

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65
Q

Using thephon curves what is the loudness in phons of a 70 dB SPL tone at 300 Hz?

A

74 phons

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66
Q

With regards to Signal Detection Theory, someone with a liberal criterion will present with thresholds that are relatively better or relatively poorer? (which one?)

A

They would have relatively better thresholds because someone with liberal criterion is more likely to press the button and say yes they heard the sound, making it seem that they perceive the low frequencies rather than someone with a conservative criterion.

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67
Q

describe the effects of signal duration on absolute threshold. What is the minimum presentation length of a pure tone to ensure valid testing?

A

Absolute threshold is the least amount of something that can be detected. If signal duration is presented for less than the minimum presentation length, the test subject may have a worse threshold because it needed to be louder for them to hear it for less than the 200 msec. If we present it at that minimum length required, their absolute threshold will be more accurate.

The minimum length of a pure tone to ensure valid testing is about 200 msec.

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68
Q

For listeners with typical hearing, a doubling of loudness is approximately equivalent to an increase of how many dB?

A

10

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69
Q

jnd for intensity

A

1 dB or better depending on presentation level

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70
Q

jnd for frequency

A

approx .5%

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71
Q

jnd for duration

A

as short as 2-3 msec

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72
Q

Why would the jnd for frequency be different at 2,000 Hz than it is at 1,000 Hz?

A

The JND is the smallest detectible change between two stimuli. For typical human hearing thresholds, the loudness perception is not the same or equal at all of the frequencies and our most sensitive frequency range is 1,000-5,000 Hz. Our JND would therefore be different at 2,000 Hz compared to 1,000 Hz because it is in the most sensitive frequency range and we would notice a larger difference at the larger frequency being 2,000 Hz.

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73
Q

List four factors that affect threshold estimation.

A

Attention level

Motivation

Understanding of the directions

Effects of habituation

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74
Q

What are the five parameters for measuring thresholds behaviorally? In other words, what are the five things that you need to decide on ahead of time when measuring a threshold of some kind?

A

Method Presentation

Starting level

Step size

Stopping rule

How we define or calculate threshold

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75
Q

Loudness is the perceptual correlate of intensity.

True or false: loudness perception is dependent upon the frequency of the stimulus

A

true

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76
Q

10 of this unit would be double the loudness of the 5 unit

A

sone scale

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77
Q

there is no relationship implied

A

phon scale

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78
Q

Using the RETSPL table below, convert 60 dB HL to dB SPL, at 2000 Hz, using TDH 49-50 headphones.

A

71

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79
Q

Your patient has a hearing threshold at 2000 Hz of 40 dB HL. You want to present a tone to them at the same frequency at 40 dB SL. At what presentation level are you presenting the tone for it to be 40 dB SL?

A

80

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80
Q

The cochlea is nonlinear, meaning that the amount of gain differs based on input level. Is more gain applied at low-level inputs, mid-level inputs, or high-level inputs?

A

low-level inputs

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81
Q

True or false: 30 dB SPL is a doubling of the pressure from 15 dB SPL.

A

false

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82
Q

For listeners with normal hearing, a doubling of loudness is approximately equivalent to an increase of how many dB

A

10

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83
Q

The human auditory system is equally sensitive at all frequencies between 20 Hz and 20,000 Hz.

A

false

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84
Q

The frequency range where the auditory system is the most sensitive is

A

1,000-5,000 Hz

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85
Q

When we test hearing, we test at a selection of discrete frequencies. When we plot the test results, we make assumptions about the hearing thresholds for the frequencies that we do not test.

For example, if the hearing threshold at 1,000 Hz is 10 dB HL and the hearing threshold at 2,000 Hz is also 10 dB HL, we assume the hearing thresholds for the frequencies between 1,000 - 2,000 Hz (1,200 Hz, for example, which we do not test) is also 10 dB HL.

Is this a correct assumption? (In other words, are we correct to assume this for each of the frequencies?)

A

false

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86
Q

A phon is a measure of

A

loudness

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87
Q

The reference for a phon is

A

1,000 Hz

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88
Q

Pitch is perceived based on maximum excitation along the basilar membrane.

A

place model

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89
Q

Bundles of auditory nerve fibers fire at the compression phase of a signal, giving the brain a cue for the period of the signal.

A

temporal model

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90
Q

Based on spectral representation of the stimulus (information contained in the spectrum).

A

place model

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91
Q

Based on the waveform of the stimulus.

A

temporal model

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92
Q

We see that a 250 Hz tone can mask a 1,000 Hz tone above certain presentation levels. What is the amount of masking when the 250 Hz tone is presented at 60 dB? (see masking curves (quiz 6)

A

28 dB of masking

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93
Q

The duration of a signal can (but may not always) affect what in terms of perception?

A

perception of tonality
absolute threshold
loudness perception

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94
Q

loudness

A

perception

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95
Q

intensity or SPL

A

physical

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96
Q

frequency

A

physical

97
Q

pitch

A

perceptual

98
Q

phase

A

physical

99
Q

duration

A

both physical and perceptual

100
Q

The jnd for frequency (also referred to as dlf) at 1,000 Hz is approximately 5 Hz. The jnd for frequency at 10,000 Hz is approximately 50 Hz. This is an example of (select the correct answer):

A

weber’s law

101
Q

Frequency selectivity refers to the auditory system’s ability to

A

detect one sound in the presence of another, different sound

102
Q

Pitch perception is affected by the presentation level.

A

true

103
Q

How does presentation duration affect absolute threshold?

A

If the presentation time is less than 200 msec, threshold will be too high

104
Q

Perception of loudness (how a person perceives the loudness of a sound) can depend on which of the following?

A

duration, frequency and bandwidth of a signal

105
Q

With this type of psychoacoustic procedure, each subsequent presentation level depends on the subject’s or patient’s response

A

adaptive procedure

106
Q

Which definition best describes frequency selectivity?

A

ask (quiz 7)

107
Q

low frequency cue

A

ITD

108
Q

high frequency cue

A

ILD

109
Q

arises due to head shadow effect

A

ILD

110
Q

sound arrives at each ear at a different point in the cycle (phase)

A

ITD

111
Q

How is the spectrum of a sound affected with transient distortion

A

spectral splatter

112
Q

How is the spectrum of a sound affected with harmonic distortion

A

distortion products are added, which are harmonics of the original signal

113
Q

How is the spectrum of a sound affected with frequency distortion

A

amplitude is reduced at certain frequencies based on characteristics fo a filter

114
Q

What is the “cocktail party effect?” (Cherry, 1953)

A

ability to attend to a target in the presence of competing noise

115
Q

better ear effect

A

as takes advantage of the fact that one ear has a more favorable SNR

116
Q

binaural squelch

A

the as takes adv of information received from both ears with different SNRs

117
Q

signal threshold improved when tones to each ear are out of phase

A

masking level difference

118
Q

copies of sound in reverberant room don’t interfere because of this

A

echo suppression

119
Q

guitar string after being plucked

A

free vibration

120
Q

tuning fork after being hit

A

free vibration

121
Q

ossicles vibrating because of music

A

forced vibration

122
Q

table vibrates when stem of a tuning fork is placed on it

A

forced vibration

123
Q

measure to avoid spectral splatter

A

5 ms ramped rise time/fall time??

124
Q

harmonic distortion

A

input level exceeds max output level

125
Q

intermodulation distortion

A

input level exceeds max output level

126
Q

linear system

A

proportionate change in input and output

127
Q

nonlinear system

A

disproportionate change in input and output

128
Q

one sound causes the threshold of another sound to be increased

A

masking

129
Q

signal and masker are presented to opposite ears; the masker in the opposite ear increases the threshold of the signal

A

central masking

130
Q

monaural masking; target signal and masker are presented simultaneously

A

psychoacoustic masking

131
Q

the masker is presented either before or after the signal or target

A

temporal masking (forward and backward masking)

132
Q

this masking takes place in the cochlea

A

psychoacoustic masking

133
Q

this masking takes place in the binaural auditory neural pathway

A

central masking

134
Q

the precise mechanism of this type of masking is unknown but it is presumed to be neural and not cochlear

A

temporal masking

135
Q

You are carrying on a conversation with a friend next to a noisy piece of equipment. Your friend’s voice (RMS amplitude) is 65 dB SPL as it reaches your ears. The level of the noise coming from the equipment is 60 dB SPL as it reaches your ears. What is the SNR?

A

5 dB

136
Q

what provides better hearing in noise

A

spatial separation of target signal and noise
binaural squelch
better ear advantage

137
Q

What would happen to the resonant frequency of a tube if the length of the tube were increased

A

resonant frequency would decrease

138
Q

The barrier is small relative to the wavelength? The barrier is large relative to the wavelength

A

sound will scatter around and fill in behind the barrier
there will be an acoustic shadow behind the barrier

139
Q

The opening is small relative to the wavelength?
The opening is large relative to the wavelength

A

sound will pass through the opening and scatter as if it is a new sound source
sound will pass through the opening unchanged

140
Q

small opening and large wavelength =

A

sound scatters and becomes new sound source

141
Q

large opening and small wavelength =

A

sound passes through unchanged

142
Q

small barrier and large wavelength =

A

sound will scatter around it and fill in behind it

143
Q

large barrier and small wavelength =

A

acoustic shadow behind barrier

144
Q

If the intensity of a sound 10 meters from the source is 36 watts/m2, what is the intensity 20 meters from the sound source in watts/m2?

A

9

145
Q

If the level of a sound 25 meters from a sound source is 40 dB SPL, what is the level 50 meters from the sound source?

A

34 dB SPL

146
Q

describes the flow of sound energy

A

acoustic immittance

147
Q

component of impedance, opposes high frequency vibration

A

mass reactance

148
Q

ease of sound flow

A

admittance

149
Q

component of impedance, frequency independent

A

resistance

150
Q

what components of impedance are frequency dependent? independent

A

mass and stiffness reactance
resistance

151
Q

opposition to sound flow

A

impedance

152
Q

component of impedance, opposes low frequency vibration

A

stiffness reactance

153
Q

begins one wavelength from the sound source

A

far field

154
Q

sound is circulating around the source and inverse square law doesn’t apply

A

near field

155
Q

part of far field, inverse square law doesn’t apply, contains reverberations

A

diffuse field

156
Q

inverse square law applies here

A

free field

157
Q

explain equal loudness contours

A

Its is the phons scale, Everything on the scale is perceived the same. Frequency affects loudness and loudness depends on frequency. All sounds on multiple frequencies at the same dB are not equally loud.

158
Q

What is dB level of a 2000 Hz tone perceived as having a loudness of 100 phons?

A

approx. 95 dB

159
Q

How is the sone scale different from the phon scale? What do we know about a sound, for example, if it is 20 sones?

A

The sone scale is different from phons because the sone scale is comparing loudness on One/ same frequency and phons is comparing loudness on/across multiple, different frequencies.
1 sone = 40 db but every plus 10 db from there is double the sone amount.
Ex: 1sone = 40db
2 sone = 50 db
4 sone = 60db
8 sone= 70 db
The sones scale will tell us the relationships between sounds. If you double the amount of sones you double the loudness. What do we know about a sound if it is 20 sones. So….

20 sones is twice as loud as 10 sones. And 20 sones is ½ as loud as 40 sones.
(this is at the same frequency)

( you use the sones scale because it tell us the relationships since its only at one frequency at a time.)

160
Q

doubling of intensity

A

3 dB

161
Q

doubling of pressure

A

6 dB

162
Q

doubling of loudness

A

10 dB

163
Q

loudness recruitment

A

defined as an abnormally rapid increase in loudness with an increase in intensity of stimulus, and it is characteristic of disorders affecting the hair cells of the cochlea

164
Q

explain loudness growth function for typical hearing, conductive hearing loss, and cochlear hearing l

A

see image

165
Q

sudden changes in sound, sound that fluctuates in amplitude at a regular rate

A

amp modulated

165
Q

What is temporal ordering? How is it assessed? Why is it important?

A

being able to process information in order that it comes in, important because of speech
assessed by syllable or words and repeat them back in correct order

166
Q

At what modulation rates (low frequency or high frequency?) is the auditory system able to detect changes in an amplitude modulated signal.

A

at low frequency rates
faster rate sounds like a steady noise to listener

167
Q

How does presentation duration affect the perception of tonality?

A

it is perceived as a click

168
Q

Minimum presentation length

A

200 msec

169
Q

temporal integration

A

adding together everything it receives in a time window

170
Q

How does presentation duration affect loudness perception?

A

Presentation duration affects loudness. Is that after a long duration, over a minute the sound begins to diminish. This is called adaptation. Loudness perception diminishes after a minute.
This is more prevalent (noticeable) at lower presentation levels because over time you will notice it less because there’s not as much going on. (the longer the duration the more itll drop off in loudness perception,)

(we are having on presentation and we are not changing the physical level. However, over time you auditory system will begin what is called adaptation. And the sound will begging to dimmish over time even though its not actually changing. Adaptation is more at lower levels because over time you will even eventually stop hearing it)

171
Q

What is it called when the loudness perception diminishes?

A

adaptation

172
Q

Is this effect more prevalent at lower or higher presentation levels?

A

lower levels

173
Q

explain the temporal model of pitch perception for pure tones and for complex harmonic sounds

A

phase locking to a period of the stimulus and a bundle of fires fire as a whole to the same period as the stimulus

174
Q

phase-locking applies up to ______ in the mammalian auditory system

A

3-5,000 Hz

175
Q

A doubling of frequency results in a doubling of pitch perception

A

false

176
Q

pitch perception is affected by intensity

A

true

177
Q

What role does pitch perception play in understanding speech in noise?

A

helps us separate one sound from another (auditory scene analysis)

178
Q

ability to hear more than one component of a sound
two tones
tones in noise

A

frequency selectivity

179
Q

shifted threshold

A

masking

180
Q

sounds softer but can still hear it

A

partial masking

181
Q

probe signal

A

test signal

182
Q

causing the masking

A

masker

183
Q

how much has it shifted by the threshold

A

amount of masking

184
Q

what is the f0 of a harmonic series with frequencies 500, 1000, 1500, 2000, and 2500

A

500

185
Q

what is the f0 of a harmonic series with frequencies 2000, 3000, 4000

A

1,000

186
Q

what is the f0 of a harmonic series with frequencies 200 and 250

A

50

187
Q

sound A is 30 dB SPL Sound C measures 100 times
the pressure. What is the dB SPL of sound C?

A

70

188
Q

Sound A is 50 dB SPL. Sound C measures 1000 times
the pressure. What is the dB SPL of sound C?

A

110

189
Q

Filter has:
amp - 0dB
center freq - 2,000 Hz
BW - 400 Hz
what are the upper and lower cutoffs? what type of filter is this?

A

band pass
upper - 2200
lower - 1800

190
Q

filter has:
amp 0dB
upper - 1,000
what type of filter is this

A

low pass filter

191
Q

filter has:
amp 0dB
lower - 1,000
what type of filter is this

A

high pass filter

192
Q

calculate the total SPL with pressure level of 46 dB SPL and BW of 100 Hz
SPL = L + 10LogBW

A

66

193
Q

Why do we use dB HL clinically?

A

Typical hearing thresholds vary by frequency. dB hearing
takes the typical hearing thresholds as measured in dB
SPL and makes them all 0 dB HL.

194
Q

convert 5 dB HL at 500 Hz to dB SPL

A

18.5

195
Q

If a patient’s hearing threshold is 15 dB and you present a
tone at 40 dB SL, at what dB HL are you presenting the
tone?

A

55

196
Q

If a patient’s hearing threshold is 45 dB HL and you
present a tone at 60 dB HL, what is the dB SL of the tone?

A

15

197
Q

Explain why threshold is a probability of a response rather
than a discrete point on a continuum.

A

this is because of our understanding of the
psychometric function. The probability of a
response changes as the stimulus increases but
below the established threshold, there is still
some probability of a response and above the
established threshold, there is a probability of a
no response. There is no single point below which
there is always no response and above which
there is always a yes response

198
Q

what is weber’s law and fraction

A

Weber’s fraction: absolute difference divided by
the value of the starting level
Weber’s law: the value of the Weber’s fraction
remains a constant, regardless of stimulus level

199
Q

other terms for differential sensitivity

A

differential threshold, jnd, difference limen

200
Q

What are direct scaling procedures? When might
we use this type of procedure?

A

A direct scaling procedure has a person establish
a relationship between a standard stimulus and a
comparison stimulus. We might use this to
understand HOW changes in stimuli are
perceived

201
Q

Describe how magnitude estimation and
magnitude production would be administered

A

Magnitude estimation: Person is given a reference stimulus and told that it has a particular value. The person assigns values to the other stimuli presented to them, based on the
reference.
Magnitude production: Same as magnitude estimation, except the person adjusts the stimulus

202
Q

Describe how ratio estimation and ratio production would be administered

A

Same as magnitude estimation and production,
except with ratios instead of a reference number

203
Q

Describe how a test using cross-modality would be administered

A

uses more than one sense. The person is asked to express the perceived magnitude for one sense in
terms of another sense. For example, express perceived magnitude for loudness in terms of a
line length

204
Q

How is a simple up-down (staircase) method administered?

A

increase stimulus following “no response”
Decrease stimulus following “response”

205
Q

How can an internal criterion be shifted? (In general.)

A

punish false positives and false negatives
Reward true positives and correct rejections

206
Q

Describe and illustrate with a sketch how a gap detection experiment or test would be administered.

A

noises presented with gaps of silence between them. Trying to find the smallest detectable gap of silence

207
Q

why does pitch of a harmonic sound stay the same even when f0 is removed

A

The fundamental frequency of a complex harmonic does not change when the physical component corresponding to the fundamental
frequency is removed because the fundamental frequency of the harmonic complex is not
changed. Phase-locking would still occur at the same rate (temporal model) and the distance
between peaks would be the same if the fundamental frequency were removed (place
model)

208
Q

process of separating sounds from a background noise

A

auditory scene analysis

209
Q

What is loudness summation and why is it evidence for auditory filters?

A

Loudness summation means that different sounds are perceived as louder, even if the level is the same, based on the nature of the sounds.
–With bands of noise, wider band signals are
perceived as louder than narrower band, even if
presented at the same level.
–With 2-tone complexes, the sounds are perceived as louder when the tones are further apart in terms of frequency.
This is evidence for auditory filters because it implies there is a critical bandwidth and sounds are perceived differently if the components of
the sounds fall within the critical bandwidth or not

210
Q

what are 3 perceptual consequences of change in auditory filter shape

A

elevated hearing thresholds (HL)
increased susceptibility to masking
pitch perception ability decreases

211
Q

why does a broader auditory filter have increased susceptibility to masking

A

With a broader auditory filter, the auditory system can not resolve the individual components of the signal and the noise. This could lead to masking occurring

212
Q

when one sound raises threshold of another

A

maksing

213
Q

occurs when one sound makes another sound more difficult to detect but doesn’t raise threshold

A

partial masking

214
Q

what factors influence amount of masking

A

Intensity of the masker
spectral characteristics of the masker relative to the maskee or tone being masked
temporal characteristics of the masker (steady state vs. fluctuating)

215
Q

Describe Fletcher’s critical bandwidth experiment. What were his findings?

A

Fletcher asked the question, “does increasing the bandwidth of the maker further raise the threshold of the maskee?” He found that increasing the bandwidth of the masker does further raise the threshold of the maskee, up to a point. Beyond that point, there is no further increase of threshold of the maskee. This lead to the model of the basilar membrane as a bank of overlapping filters. Filter bandwidth is approximately 19% of the center frequency.

216
Q

on frequency listening

A

peak is at region on bm that is best frequency and that part of the bm is responding

217
Q

off frequency listening

A

another part was responding

218
Q

Why is a broader filter more susceptible to masking?

A

if sounds dont fall in same filter they are less likely to mask and if they are in the same one they are more likely to mask

219
Q

binaural fusion

A

separate signals from each ear are perceived as a single fused auditory image

220
Q

ability to improve perceptual performance on psychoacoustic tsak

A

binaural summation

221
Q

f you had a patient with symmetrical
hearing thresholds and you fit them
with hearing aids providing the exact
same amount of amplification, would
there be a difference in loudness
perception if the patient wore only
one or wore both of the hearing aids?

A

Yes, it would be almost twice as loud
with both of the hearing aids in, due tobinaural loudness summation

222
Q

azimuth

A

horizontal plane

223
Q

elevation

A

vertical plane

224
Q

directly in front

A

0 azimuth

225
Q

directly to right

A

90 azimuth

226
Q

directly to left

A

270 azimuth

227
Q

directly behind

A

180 azimuth

228
Q

How do interaural level differences
(ILD) arise? Is this a low frequency or a high frequency cue for sound source localization

A

LD’s arise because of the head
shadow. Sound is reflected off of the
head and casts an acoustic “shadow”
on the opposite side. The sound level is greater on the side where the sound
originated. This is a high frequency cue for sound source localization.

229
Q

How do interaural timing differences
(ITD) arise? Is this a low frequency or a high frequency cue for sound source localization?

A

ITD’s arise because a sound arrives to
one ear sooner than it arrives to the
other. This is a low frequency
phenomenon.

230
Q

same stimulus

A

diotic

231
Q

differs in one dimension

A

dichotic

232
Q

describe the precedence effect

A

says that the sound source localization is based on first copy of the sound to arrive to the as

233
Q

two sounds with slightly different frequency co occur, compressions
and rarefactions overlap a portion of the time; perception is of a single
tone with fluctuating amplitude

A

beats

234
Q

describe the doppler effect

A

Sound waves change when sound source is a moving object.
Perceptually, this results in a change in pitch. Sound moving away
from listener, wavelengths elongate, pitch lowers. Sound moving
towards listener, wavelengths are compressed, higher perception of
pitch

235
Q

what causes standing waves

A

two waves moving in exact opposite directions, having same amp and freq

236
Q

Name 3 instances where
standing waves are of
importance to an
audiologist.

A

Calibration issues when the ear canal is involved
Hearing aid measurements
Sound field testing

237
Q

Explain why smaller animals have
better high frequency hearing,
based on ossicle size

A

They have smaller ossicles so their middle ear system can vibrate at high frequencies but not so much at low frequencies

AUDE 5140 - Acoustics (23 decks)

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