Impact of Auditory Damage on Perception

Question 1

What percentage of the population with hearing loss has a mild to moderate loss?

Answer 1

75%
10% aided
90% unaided

Question 2

What percentage of the population with hearing loss has a moderate to severe loss?

Answer 2

20%
50% aided
50% unaided

Question 3

What percentage of the population with hearing loss has a profound loss?

Answer 3

5%
70% aided
30% unaided

Question 4

What are some things that impact speech intelligibility when good ears go bad?

Answer 4

Signal audibility
Dynamic range
Frequency resolution
Temporal resolution
Spatial hearing

Question 5

What is the impact of threshold loss on audibility?

Answer 5

Audibility of softer phonemes becomes difficult
The degree of threshold loss is disproportionate (greater in highs typically)
Listeners perceive the volume as “loud enough” (low freq) despite inaudibility of consonant sounds (high freq)

Question 6

Does audibility of high frequency sounds support intelligibility?

Answer 6

Yes
35% of speech intelligibility comes from audibility of speech signals at 2 kHz
95% of speech intelligibility comes from audibility of speech signals ranging from 500 to 5000 Hz

Question 7

What is the impact of hearing loss on the dynamic range?

Answer 7

OHC damage results in loss of amp of soft sounds while IHC continue to detect louder sounds
Abnormal loudness growth

Question 8

What is linear amplification?

Answer 8

Adds an equal amount of gain to soft, moderate, and loud input levels
Doesn’t take reduced dynamic range into account

Question 9

What is non-linear amplification?

Answer 9

Uses compression to increase the intensity of soft signals while decreasing the intensity of sound signals

Question 10

What is another name for non-linear signal processing?

Answer 10

Automatic gain control

Question 11

Does abnormal loudness growth vary by frequency?

Answer 11

Yes
Frequency specific compression is needed
Frequency compression ratios

Question 12

How are the compression ratios in todays hearing aids manipulated?

Answer 12

Frequency shaping channels

Question 13

What is the impact of hearing loss on frequency resolution?

Answer 13

Basilar membrane no longer produces sharp tuning curves
Primary signal is no longer enhances making it difficult to differentiate the desired signal from the undesirable signal

Question 14

What is the impact of hearing loss on temporal resolution?

Answer 14

Becomes harder to detect small time-related changes in an acoustic signal
Signal could become blurred or smeared

Question 15

What are some things that time awareness helps us with?

Answer 15

Gap detection (spoon vs soon)
Phonemic duration (need vs neat)
Temporal ordering (boots vs boost)
Suprasegmentals (patterns of stress, intonation, and rhythm)

Question 16

What does the temporal envelope refer to?

Answer 16

The slow overall change in intensity over time

Question 17

What do temporal envelope cues support?

Answer 17

Speech intelligibility in quiet
Supplies cues on manner of articulation, consonant voicing, duration, and prosody

Question 18

What does the temporal fine structure support?

Answer 18

Detection of speech and non-speech signals in noise
Vowel identification and consonant place of articulation

Question 19

What does a loss of the ability to detect temporal fine structure result in?

Answer 19

An inability to extract information from the mixture of sounds conveyed between rapidly fluctuating speech signal and noise

Question 20

Does the audibility of suprasegmental cues help the listener pick out one voice from another in noise?

Answer 20

Yes

Question 21

What is spatial hearing?

Answer 21

Makes it possible to tell where sound is coming from in space
Lets us focus on one signal over another

Question 22

What is the auditory space?

Answer 22

Surrounds an observer and exists wherever there is sound
Azimuth, elevation, and distance

Question 23

Does spatial hearing rely on binaural hearing and auditory processing systems to compare signals arriving at one ear from those arriving at the other?

Answer 23

Yes
ITD
ILD
Pinna for elevation cues

Question 24

Is timing a low frequency cue?

Answer 24

Yes

Question 25

Is level a low frequency cue?

Answer 25

No

Question 26

What are some benefits to spatial hearing?

Answer 26

To determine the location of a sound source
Unmask sounds otherwise obscured by noise
Shift our attention and focus on one sound source while ignoring another
Feel connected with the environment

Question 27

What happens in ILD?

Answer 27

Reduction in sound level occurs for high frequency sounds for the far ear
Head casts an acoustic shadow
Occurs because low frequency sounds are not attenuated much by the head

Question 28

What is the head related transfer effect?

Answer 28

It is the effect that the head and the pinna has on intensities of frequencies (amplitude peaks and notches in the high frequencies differ based on the angle they arrive from)

Question 29

Does each pinna interact with incoming sounds differently depending on where the sound source is?

Answer 29

Yes
This provides a monaural spectral cue that is helpful in locating sounds that occur above or below and in front or behind us

Question 30

Does the location of the mic on a hearing aid affect the identification of monaural spectral cues?

Answer 30

Yes

Question 31

Can single sided deafness still allow some degree of localization due to cues from the pinna?

Answer 31

Yes

Question 32

What are some things that an audiologists needs to know that the recommended hearing aid can supply?

Answer 32

Audibility for high frequency interaural level differences (>3 kHz)
Audibility for low frequency interaural timing differences (> 850 Hz)
Considers the impact of mic position on the audibility of monaural spectral cues (HRTF)

Question 33

Are audiograms predictive of the activity limitations resulting form a hearing loss?

Answer 33

No
Audiometric thresholds are not predictive of communication ability