380 Final

Front 1

What factors can make auditory system abnormal?

Back 1

noise exposure
ototoxic substances
disease/infections
aging
genes

Front 2

describe in a graphic way how loud noise cause damage to the auditory system.

Back 2

Mechanic tearing of the structure, much like a tornado making a touch down in the inner ear, and tearing the delicate structure apart. While some of the minimal damage may be reversible, others are permanent. Ther may also be subtle ways of damage, for ex: the noise may also cause disorder in metabolic functions of the inner ear.

Front 3

There are two components that make up the threshold shift due to noise exposure- what are they?

Back 3

TTS and PTS

Front 4

What is asymptotic threshold shift (ATS) and how long does it typically take TTS to reach ATS?

Back 4

The upper limit of TTS;
It takes about 15 hours to reach ATS

Front 5

Why is TTS usually expressed as the threshold shift estimated at a delay of 2 to 4 minutes in stead of right away following the termination of the noise stimulation?

Back 5

Bc it takes time- a few minutes- to estimate the thresholds

Front 6

How does the threshold shift depend on stimulus level and duration?

Back 6

Noise at lower level may cause the same amount of threshold shift by longer exposure. A really rough approximation is 3-5dB drop in level for every doubling the duration

Front 7

Why does a white noise exposure cause the maximum threshold shift near 4000 Hz?

Back 7

Ear-canal resonance

Front 8

How much time does it typically take for threshold to recover to near normal level (or TTS to be near 0) ?

Back 8

about 20 hrs, largely independent of the initial TTS value

Front 9

When the loud sound is a tone, near what fq do you expect to observe the maximum TTS?

Back 9

1/2 octave above the stimulating fq. To get f that is approx 1/2 octave above fo, multiply fo by 1.4
EX: 1/2 octave above 1kHz is 1.2 kHz. It will be 4.2 kHz for fo=3 kHz

Front 10

Below what level is noise exposure not considered unsafe?

Back 10

75 db SPL

Front 11

In what way does ototoxic substances cause damage to the auditory system?

Back 11

They are poisionous to the tissues and can cause problems to both hair cells and stria vascularies

Front 12

What is a most common medicine that can be ototoxic?
What are the symptoms?

Back 12

Aspiring
Tinnitus; hearing loss, when take in large doses

Front 13

What term is used to describe HL due to aging?

Back 13

presbycusis

Front 14

Why is presbycusis typically started at high fq?

Back 14

BM near the base wears out first

Front 15

In which animals do hair cells regenerate?

Back 15

Birds
fish?

Front 16

For what degree of HL are hearing aids most suitable?

Back 16

moderate- severe

Front 17

for what degree of HL is a CI most suitable?

Back 17

severe to profound

Front 18

of what proportion of ppl who need hearing aids actually own hearing aids?

Back 18

25%

Front 19

Why has it been said that making hearing aid user happy is a tough business? (compared to eye glasses)

Back 19

Bc theres stigma, people are unmotivated, complicated devices, costly, rarely work great

Front 20

What are the four most common types of modern hearing aids?

Back 20

BTE, ITE, ITC, CIC

Front 21

What are the pros and cons of reducing the size of hearing aids?

Back 21

The smaller the more cosmetically appealing, but sacrifice the power

Front 22

what is the consequence of conductive haring loss?

Back 22

you are losing sensitivity

Front 23

What type of amplification is suitable for the conductive loss?

Back 23

linear

Front 24

what are the four major consequences of sensorineural HL?

Back 24

loss of sensitivity, lost dynamic range, lost spectral(frequency) and temporal resolutions

Front 25

What type of amplification is suitable for the SNHL?

Back 25

compression

Front 26

How are soft and loud sounds amplified with non-linear compressive hearing aids?

Back 26

more amplification for soft sound, less amplification for loud sound

Front 27

Know how to explain the linear vs non-linear (compression) amplification using the loudness growth functions of normal and impaired ears

Back 27

conductive parallel, non-linear loud sound is smaller gain for loud sound

Front 28

List 3 major components of hearing aids

Back 28

microphone, amplifier, receiver

Front 29

of which inner ear structure is the function similar to the function of hearing aids?

Back 29

OHC

Front 30

List the major components of CIs

Back 30

1) directionality, 2 mics, enhance sensitivity to the front-improving speech intelligibility. Can improve signal to noise ratio.
2) noise reduction- backroung noise attenuated leaving the speech intact.
3) feedback cancellation-
cancels feedback

Front 31

List the major components of cochlear implants

Back 31

Microphone, speech processor, transmitter, receiver (delivers stimulus to electrode), goes to cochlear

Front 32

Of which inner-ear structure is the function similar to the function of CIs

Back 32

IHCs

Front 33

*Explain why CIs have poor music perception

Back 33

Insertion of the electrodes stops short of the apex -that’s where low fq are stimulated. Low fq are essential for pitch perception- so there is no melody

Front 34

In CI signal processing, which level of temporal cues are omitted, and which level of temporal cues are preserved?

Back 34

Temporal 2 cues:
Rapid (omitted) and Slow (preserved)
If fast cue is preserved improved pitch

Front 35

Give one example that signifies the performance of today's CIs

Back 35

talking on the phone

Front 36

How are hearing aids and CIs combined to overcome each other's limitations?

Back 36

Hearing aids are good for low fq
CI good for high fq (bc its at the round window)