It's something I just don't get and id like to understand why! Ive seen some who have enough residual hearing to be aided to 15db in the major frequencies with powerful HAs consider or get CI. Very few people get to 15db with CI. How will 40db, 30db, even 20db with CI not be worse than 15db with powerful HAs?
In another thread, I have shown that at 20db you have access to 90% speech, at 30db it drops to 75% and at 40db it's just 50%. I know that CI might give better quality hearing than severe-profound deafness, but what about quantity? This is just as important as quality, you should not trade one for another but attempt the best of both. This becomes possible with a 100+ db loss but for losses under 100db and especially under 80db, one should easily get good aided hearing with powerful HAs.
Let's give examples.
Person 1 hears at 30db unaided and scores 75% speech unaided. He tries mini open fit HAs which aids him to 10db and improves his speech to 95%. This is only 5% less than the 100% that his hearing friend who hears 10db unaided scores.
Person 2 hears at 60db unaided and can't hear any speech without HAs. One audiologist suggests mini open fit HAs which aid him down to 30db. He scores 70% speech with those HAs. He sees another audie who recommends more powerful HAs. He tries those and is aided to 10db and scores 90% speech and hears alot more sounds as well.
Person 3 has a 80db loss and tries HAs which aid him to 30db which results in 60% speech score. Not satisfied, he sees another audiologist which fits him with proper HAs and programs them for maximum gains. He hears aided down to 10db and scores 80% speech.
Person 4 is profoundly deaf with 100db loss and is scoring 0% speech with his old HAs that aid him down to 50db. He is recommended for a CI. This CI audiologist has ethics and makes sure he first tries the best HAs. He is fitted with the same HAs as person 3 and hears at 30db aided. This results in him able to understand 40% speech. The CI audiologist pronounces him a borderline CI candidate. He decides on CI anyway.
With CI, he hears 30db aided. This results in a 60% speech score which is a decent improvement. He and his CI audiologist keep working to try to improve his results. After much trial and error over several months, the audiologist finally finds a map that allows him to hear at 20db! This boosts his speech score to 75%! He is happy with CI!
------------------------------------------
Those are just examples but the improvement with more amplification is constant. After all, you end up further up on the speech banana. To end on the top, you need to hear at 10-15db. Mild losses start at 25db since this is the point when you start missing 15% to 20% of the speech banana.
You may have noticed two factors to hearing: Quantity and Quality. Ive been doing my research and learned that outer hair cells only account for 5% of the auditory information. The OHC's account for 50-65db of hearing while the IHC's account for another 25db or so. It's the OHCs that are the first to go and as the loss progresses into the severe range, the IHC's start going. In the profound range, dead zones become common.
http://www.scielo.br/pdf/rboto/v73n4/en_a16v73n4.pdf
without cochlear dead
zones presented 79.1% and 55.2%, respectively, indicating
the benefit provided by amplifying the high frequencies.
Under the same conditions mentioned above, patients
with dead zones in their cochleas presented SRT 41.1%
and 39.3%, respectively, without statistically significant
difference between the two last values mentioned.
I viewed a powerpoint presentation that stated mild and moderate losses retain excellent speech comphrension when properly aided and that severe losses could result in poor to good speech comphrension. Profound losses generally result in poor speech comphrension. This has to do with cochlear dead zones.
Ive also read that "decent" looking audiograms but with unusually poor speech scores are highly suspect of cochlear dead zones. That 80db "response" at 2000Hz, 85db at 3000Hz, 90db at 4000Hz for example may arise from off-frequency stimulation. The 1500Hz zone at 50db HL may be activated by the intense high frequency sounds. The pitch at 1500Hz and up may sound essentally identical!
In another thread, I have shown that at 20db you have access to 90% speech, at 30db it drops to 75% and at 40db it's just 50%. I know that CI might give better quality hearing than severe-profound deafness, but what about quantity? This is just as important as quality, you should not trade one for another but attempt the best of both. This becomes possible with a 100+ db loss but for losses under 100db and especially under 80db, one should easily get good aided hearing with powerful HAs.
Let's give examples.
Person 1 hears at 30db unaided and scores 75% speech unaided. He tries mini open fit HAs which aids him to 10db and improves his speech to 95%. This is only 5% less than the 100% that his hearing friend who hears 10db unaided scores.
Person 2 hears at 60db unaided and can't hear any speech without HAs. One audiologist suggests mini open fit HAs which aid him down to 30db. He scores 70% speech with those HAs. He sees another audie who recommends more powerful HAs. He tries those and is aided to 10db and scores 90% speech and hears alot more sounds as well.
Person 3 has a 80db loss and tries HAs which aid him to 30db which results in 60% speech score. Not satisfied, he sees another audiologist which fits him with proper HAs and programs them for maximum gains. He hears aided down to 10db and scores 80% speech.
Person 4 is profoundly deaf with 100db loss and is scoring 0% speech with his old HAs that aid him down to 50db. He is recommended for a CI. This CI audiologist has ethics and makes sure he first tries the best HAs. He is fitted with the same HAs as person 3 and hears at 30db aided. This results in him able to understand 40% speech. The CI audiologist pronounces him a borderline CI candidate. He decides on CI anyway.
With CI, he hears 30db aided. This results in a 60% speech score which is a decent improvement. He and his CI audiologist keep working to try to improve his results. After much trial and error over several months, the audiologist finally finds a map that allows him to hear at 20db! This boosts his speech score to 75%! He is happy with CI!
------------------------------------------
Those are just examples but the improvement with more amplification is constant. After all, you end up further up on the speech banana. To end on the top, you need to hear at 10-15db. Mild losses start at 25db since this is the point when you start missing 15% to 20% of the speech banana.
You may have noticed two factors to hearing: Quantity and Quality. Ive been doing my research and learned that outer hair cells only account for 5% of the auditory information. The OHC's account for 50-65db of hearing while the IHC's account for another 25db or so. It's the OHCs that are the first to go and as the loss progresses into the severe range, the IHC's start going. In the profound range, dead zones become common.
http://www.scielo.br/pdf/rboto/v73n4/en_a16v73n4.pdf
without cochlear dead
zones presented 79.1% and 55.2%, respectively, indicating
the benefit provided by amplifying the high frequencies.
Under the same conditions mentioned above, patients
with dead zones in their cochleas presented SRT 41.1%
and 39.3%, respectively, without statistically significant
difference between the two last values mentioned.
I viewed a powerpoint presentation that stated mild and moderate losses retain excellent speech comphrension when properly aided and that severe losses could result in poor to good speech comphrension. Profound losses generally result in poor speech comphrension. This has to do with cochlear dead zones.
Ive also read that "decent" looking audiograms but with unusually poor speech scores are highly suspect of cochlear dead zones. That 80db "response" at 2000Hz, 85db at 3000Hz, 90db at 4000Hz for example may arise from off-frequency stimulation. The 1500Hz zone at 50db HL may be activated by the intense high frequency sounds. The pitch at 1500Hz and up may sound essentally identical!
