How much sound should cochlear implants capture

1
How much sound should cochlear implants capture?

• Can a wide Input Dynamic Range (IDR) improve
  performance?
• Normal speech 60dB
• Quiet conversation 55dB
• Background noise 40dB

2
Input Dynamic Range (IDR)

• Coding speech in noise using a 60 dB IDR
• Less than half of the recipients electrical
  dynamic range is available for speech.

Recipients dynamic range
Input acoustic signal
100
C
70
Output current level
T
40
Input signal intensity (dB SPL)
10
0
3
Input Dynamic Range (IDR)

• Coding speech in noise using a 32 dB IDR
• Most of the recipients electrical dynamic range
  is available for speech

Recipients dynamic range
Input acoustic signal
100
C
70
Speech
Output current level
T
40
Input signal intensity (dB SPL)
Noise
0