Wk12 - 30-Programming Parameters

Question 1

What is MAPing?

Answer 1

The Programming

• Maxbox is the interface b/w the computer and speech processor
• goal is to generate comfortable and useable stimulation parameters

Question 2

What is the goal of the AGC Compression Ratio?

Answer 2

To accurately represent loudness variations in dynamic acoustic environments

Question 3

What are the 2 steps involved in the AGC Compression Ratio accurately representing loudness variations?

Answer 3

1) Dynamic - AGC is slow and fast acting across all manufacturers; Cochlear now has a medium acting band as well (i.e. Dual-loop AGC)
- slow detector reacts to changes in volume and is in control the majority of the time
- fast detector kicks in when loud transient sounds occur to compress the DR rapidly

2) Converting IDR to EDR
- static process influencing how different sounds are amplified in the EDR
- all companies do this differently and have different terms for it (Cochlear = Q-value; linear relationship. Med-EL = MAPLAW; asymptotic or s-shaped relationship)

Question 4

Do the frequency range and allocation vary by manufacturer?

Answer 4

Yes; frequency allocation can be set as a default or adjusted by the clinician in some cases
- frequency allocation dictates the bandwidth of each channel

Question 5

What affects the frequency range and allocation?

Answer 5

• disabling of electrodes
• processing strategy (ie. Fine structure strategies vs others)
• hearing configuration (Ie. EAS)

Question 6

Pulse width/duration is ______ (linearly/inversely) related to stimulation rate

Answer 6

Inversely

• pulse width/duration controls the area of excitation that each electrode provides stimulation (ie. wider pulse width = wider spread of excitation)
• e.g. more spectral smearing
• pulse width/duration is the primary parameter being manipulated in Oticon Medical devices for loudness growth

Question 7

_____ ______ is the primary parameter being manipulated by Advanced Bionics, Cochlear, and Med-EL devices for loudness growth

Answer 7

Pulse Amplitude

Question 8

What is stimulation rate?

Answer 8

How fast electrical pulses are being sent out to stimulate the AN
Two types:
- per channel stimulation rate; number of pulses emitted per second on any given channel
- total stimulation rate: per channel stimulation rate x # of channels

Question 9

What is Channel Gain

Answer 9

• available with Advanced Bionics and cochlear software
• allow (de)emphasis of the input on individuals channels pre-processing
  (e. g. give emphasis above 4kHz for individual having difficulty hearing ‘s’)

Question 10

What is the number of maxima?

Answer 10

Used in N-of-M strategies to determine the amount of info used to stimulate the nerve at any one given point in time

Question 11

What are examples of front-end processing features?

Answer 11

Mic directionality
ADRO
Wind noise reduction
BG noise reduction
AGC

Question 12

Microphone directionality may be _____ or automatically adaptive

Answer 12

Fixed

Question 13

All devices have a(n) ___-directional mode

Answer 13

Omni-directional

Question 14

Directional modes of microphones apply ___ _____ to (de)emphasize sounds in specific areas

Answer 14

Polar Plots
Examples:
Ultrazoom, Stereozoom (Advanced Bionics)
Fixed, Zoom, Adaptive Beam, ForwardFocus (Cochlear)
Natural, Adaptive (Med-EL)
Omni, Partial directionality, total directionality (Oticon)

Question 15

Features impacting speech clarity are used to:

Answer 15

Improve speech accessibility compared to BG noise

AB: SoftVoice, ClearVoice, Echoblock, Windblock (also in Phonak)
- SoftVoice - attempts to enhance volume of soft speech
- ClearVoice - 3 diff settings to make average speech more salient vs BG noise
Cochlear: ADRO, ASC, SNR-NR (BG NR), WNR (wind NR)
- adaptive dynamic range optimization
- auto sensitivity control - changes relative input based on BG noise
Med-EL: Sensitivity, Adaptive Intelligene, Ambient NR, Transient NR, Wind NR
- sensitivity needs to be adjusted by listener
- AI - integrates other features based on environment to optimize speech
Oticon: SpeechGuard, Voice Track, Wind NR