Mapping a Cochlear Implant

[Phi4Sius]

I really like this article on MAPPing, although the explanation of CI dynamic range seems to be incorrect (AB has an 80 dB dynamic range). If I am misunderstanding their usage of the term dynamic range and their advising that CIs only have a 6-15 dB dynamic range, I apologize in advance.

It also provides for a good explanation of why regular mappings are essential and why CIs won't work well if you don't go for regular mappings.

Mapping a Cochlear Implant - Hearing Pocket

 

[deafdude1]

I posted that article before and was explained that CIs today have 30+ db dynamic range. Your threshold(T) is the faintest sound you can hear, say 30db and your comfort(C) is the loudest sound you can hear without pain, say 70db. The difference of 40db is your dynamic range. Hope this helps.

Check this by the way:

http://www.alldeaf.com/hearing-aids-cochlear-implants/71006-good-article-talks-about-ci-mapping.html

 

[john57]

Phi4Sius,

There is a bit misunderstanding on what the IDR on the AB implant means. That is the input dynamic range that the microphone input circuits can handle. However the article is not talking about the IDR but the electrical output dynamic range in the cochlea which is 6-15dB in current levels not in sound pressure level.
The default IDR setting on the AB is 60db. Since you do not have a large Output Dynamic Range you do not want a large IDR either since if you have a 80DB for the IDR then you will have to compress the sounds more to fit within the more limited output dynamic which can make sounds harder to understand instead of better. That is why AB makes their IDR adjustable to fit with the output capabilities of the users.
The Med-EL implant uses a fixed IDR but moves with sounds levels in the environment like a sliding window so that is can cope better in a large dynamic range environment. Each manufacture does things with their IDR a bit different.

I really like this article on MAPPing, although the explanation of CI dynamic range seems to be incorrect (AB has an 80 dB dynamic range). If I am misunderstanding their usage of the term dynamic range and their advising that CIs only have a 6-15 dB dynamic range, I apologize in advance.

It also provides for a good explanation of why regular mappings are essential and why CIs won't work well if you don't go for regular mappings.

Mapping a Cochlear Implant - Hearing Pocket