Wk5b - Func. Channels, Speech, Music, & Environment sounds

Question 1

What is the difference between electrodes and channels?

Answer 1

Electrode - physical component that delivers/collects current in the cochlea; fixed
Channel - combination of signal processing algorithms and physical components pertinent to a bandwidth; in some cases, each channel has a corresponding electrode, in others the output is mixed, or additional virtual channels are created

Question 2

Why might NH listeners be used in a study evaluating SIN testing with varied channels of stimulation and SNRs?

Answer 2

• can investigate the channel issue alone (separate from the anatomical issues)

Question 3

T/F: Both NH and CI users do better and better with SIN scores when they have access to more channels (regarding consonant perception).

Answer 3

False: Normal hearing listeners did better, CI users did better UP UNTIL about 8-10 electrodes

Question 4

In the 2001 study testing SIN scores for CI users and NH listeners using vocoder simulations, what trend did we see with vowel perception when S/N values decreased to 0dB?

Answer 4

SIN scores decreased

Question 5

According to the 2001 study, N electrodes ____ (do/do not) guarantee N independent channels of information

Answer 5

Do not

Question 6

What are some important elements of musical sound?

Answer 6

Melody (pitch)
Rhythm (timing)
Dynamics (varying loudness)
Timbre (Temporal and spectral envelopes)
Harmony (multiple concurrent sources)
Lyrics (speech with music)

Question 7

How might CI speech processing affect elements of musical sound?

Answer 7

Timbre, fine structure (melody), harmony, and lyrics may be affected due to the loss of fine structure
Rhythm would probably be okay

Question 8

Most CI users have great difficulty perceiving what 2 musical elements?

Answer 8

Melody

Harmony

Question 9

What type of music (string, etc) is easier to follow for CI users?

Answer 9

Percussive

Question 10

Regarding music, CI users perform close to NH listeners in _____ _____ discrimination, and in detecting _____ changes.

Answer 10

Rhythmic pattern; tempo changes

Question 11

Timbre depends on temporal _____ and _____ profile

Answer 11

temporal envelope; spectral profile

Question 12

Did CI users perform better identifying melodies with or without lyrics?

Answer 12

With

Question 13

When rhythmic cues were no longer available, NH listeners identification performance dropped to 77%, and CI user performance decreased by ____

Answer 13

Half (20% correct to 10%)

Question 14

How did Ioan describe semitones (hint: piano)?

Answer 14

The difference between neighbouring keys (e.g. black key and white key)

Question 15

CI users’ JND for pitch discrimination is ~____%

Answer 15

7% or 1 semitone

Question 16

T/F: Based on the study by Won et al, if a participant can discriminate between a stimuli and an inverted stimuli at 0.5 ripples/octave, then they can perceive 0.5 ripples per octave

Answer 16

True; this test was repeated at 1, 2, and 4 ripples/octave - at 4 ripples/octave, the two stimuli were almost the same.
- participants who were better at spectral ripple detection were also better at melody and timbre discrimination, as well as semi-tone JND

Question 17

Which environmental sounds (from Macpherson’s simulation) were the easiest to perceive?

Answer 17

Those with familiar temporal sounds (e.g. helicopter, toilet flushing, dog barking)

Question 18

On average, CI users are significantly worse at identifying ____ sounds than identifying sentences in quiet

Answer 18

Environmental

Question 19

Simulations with ___ channels are the best indicators of typical CI performance

Answer 19

8-channels (as good as they are, there are still many challenges)