extra cards

Question 1

what are the different ear mold styles?

Answer 1

standard mold
--carved shell
-skeleton mold 
--semi-skeleton
canal mold
--canal lock, canal, hollow canal
Cros
-A (part concha-rim cut out and full canal), B (full concha with full canal), C (full concha with short canal)

Question 2

peri-tympanic

Answer 2

where the CIC sits, deeply seated

Question 3

IROS vent

Answer 3

when the vent path in the ITE/ITC is opened out by removing some of the shell at the medial/lateral ends of the vent leaving the vent path

Question 4

problems with the Y vent design

Answer 4

HF sounds propagating down the sound bore will be partially reflected @ the Y junction.

1. this decreases HF gain
2. makes HF feedback oscillation more likel

Question 5

disadvantages of open-canal fitting

Answer 5

• gain-frequency response
• avoids own-voice occlusion
• feedback oscillation
• microphone directivity and adaptive noise reduction
• prescription targets and real-ear gain measurements

Question 6

reasons to mix impression material with a spatula and disposable pad/cleanable surface

Answer 6

• adverse health consequences for clinicians from repeated absorption of chemicals
• contaminating impression material w/sulfer based substances that leak from hands or latex gloves
• raising the temp. of the impression material because setting time decreases

Question 7

input controlled compression

Answer 7

volume control is after the compressor in the HA.
compression commences at the same input SPL for all setting of volume control.
once the compressor has done its job, the volume control determines the size of the output signal. the curve moves up and down as volume control is varied

Question 8

output controlled compression

Answer 8

volume control affects signal BEFORE the signal reaches the compressor. the curve moves left to right.
if the volume gets controlled down, then the compression factor may not be necessary because the initial volume is down.

Question 9

shapes of polar directivity pattern

Answer 9

cardioid
super-cardioid
hyper cardioid
figure-8 / bi-directional
(sensitivity lobe)

Question 10

wiener filter

Answer 10

the signal power divided by (signal power + noise power)

Question 11

what should a comprehensive evaluation of frequency lowering measure?

Answer 11

• ability to detect HF speech sounds and environmental sounds
• ability to identify a wide range of consonants with high representation of fricatives from female voice, but not restricted to HF consonants
• detection and ID in both quiet and in noise
• impact on speech production
• changes in these abilities over several months

Question 12

what are some aspects of speech cue enhancement?

Answer 12

enhancement of:
spectral shape
consonant-to-vowel shape
duration
re-synthesis
transient enhancement
speech simplification

Question 13

what can an audiologist tell by data logging?

Answer 13

• use of volume control
• if client is actually using the HA
• battery usuage
• use of programs
• usage of 1 HA compared with the other
• usage of a program for a short period of time, indicating a troubling environment for the patient