Part 4.1

Question 1

Which of the following is not considered to result from the successful use of open canal fittings:

a) Localization
b) High freq assistance because of low freq suppression
c) Pressure relief in the ear canal
d) Tolerance problem relief
e) Some reported improvement in speech discrimination

Answer 1

a) Localization

Open canal fitting means the fellow already has good localization, so you can’t improve something the fellow already has.

Question 2

A vent while providing an escape pathway for amplified sound from the hearing aid can also lead to:

a) Compression
b) Distortion
c) Feedback
d) Low frequency emphasis
e) Increase gain

Answer 2

c) Feedback

Question 3

All but one of the following are true about venting:

a) increases gain in the high frequencies
b) With vent below 3mm in diameter, some low freq gain can occur
c) Pressure relief occurs with vents as small as .025”
d) May reduce the occlusion effect if large enough
e) It generally provides for extreme low freq suppression

Answer 3

e) It generally provides for extreme low freq suppression

Letting sound escape isn’t going to suppress sound.

Question 4

One of the following does not apply to the CLASSIC CROS

a) Has microphone on the poor ear side
b) Uses an open earmold
c) Uses the head shadow effect
d) Improves hearing for a unilateral loss
e) Has the amplifier and the receiver on the good ear

Answer 4

c) Uses the head shadow effect

If you route signals then you are avoiding any head shadow effect.

Question 5

One of the following statements is not true about BiCROS:

a) Off side microphones to overcome head shadow effect
b) Two microphones
c) Two signals to both ears
d) Earmold is generally close type to better ear
e) For some, two sided hearing with one hearing aid

Answer 5

c) Two signals to both ears

BiCROS is for people with poor hearing in one ear.

Question 6

Air-Conduction receivers are mostly:

a) Magnetic
b) Ceramic
c) Electret condenser
d) Carbon
e) Crystal

Answer 6

a) Magnetic

A receiver is a ‘speaker.’ Find a graphic of the parts of a speaker.

Question 7

In terms of its effect on the frequency response the weakest link in the hearing aid is the:

a) Microphone
b) Receiver
c) Amplifier
d) Power supply
e) Telephone coil

Answer 7

b) Receiver

The receiver is the last item in the chain of parts that is a hearing aid. It doesn’t do anything, it just relays sound.