I’ve been investingating amplification capabilities for different CIC hearing aids and it appears that the Widex Inteo CIC has more gain capabilities than most other CIC hearing aids. Although it is hard to determine since some manufacturers do not provide gain specifications, limited gain specifications, or hard to compare gain specifications, if some judgements are made, the Widex Inteo CIC seems to perform fairly well in this area.
Although the Widex Intero CIC appears to be only average with other top CICs when the input SPL (Sound Pressure Level) is 90 DB, it seems to perform better than most when the input SPL is 60 DB. It also has a very strong Max Gain of 61 DB at lower input SPL DBs. Also what also appears to be nice is that it has a fairly high consistant gain between 2 kHz and 3.1 KHz using a 60 SPL DB input (lower input SPL DBs usually follow a similar pattern). Most other CICs peak in that frequency range and then quickly fall off.
The Max Gain appears to be well above the other CICs but this may or may not appear as it seems. Some other CICs relate that number without defining what input SPL DB is being used (same as the Widex Inteo) where as others relate that number using a input SPL of 50 DB. If the Widex Inteo CIC can only produce that gain at very low input SPL DBs (10-20 DB for example), then it may not perform any better than other CICs that have a Max Gain of about 45 using a 50 DB input SPL.
My concern about a CIC with 50-60dB of gain would be feedback. Even with today’s best feedback management technology, it would be difficult to control at these power levels.
Also, CICs produce more “subjective gain” to the wearer because of the proximity of the receiver to the eardrum. A 50dB CIC might be comparable to a 60-65dB traditional BTE.
Finally, if this instrument is for you or a loved one, what does their audiogram look like? I don’t like the idea of audie’s fitting severe or profound losses with CICs. I really believe you are sacrificing performance for cosmetics.
Yes, on the specs, it appears that they are some of the most powerful CIC’s.
Yet, at Bherring stated, feedback will almost 100% be an issue, and keeping that much sound pressure in the ear will almost be impossible, even with laser 3D shells, feedback cancellation schemes, etc.
Thus, if this much power is required, as stated earlier, if the hearing loss is severe to profound, BTE is the way to go. If cosmetics is an issue, look at the Phonak MicroPower. They are very small BTE’s with a receiver in the ear design housed in a small CIC case.
About 6 years ago I had a hearing test and if I remember correctly the audiogram indicated upto 55 DB on the upper 2 kHz-4kHz frequencies (lower frequencies were in the normal range). I was fitted with a Siemens top of the line CIC hearing aid and over the next month I went back to the audiologist several times for readjustments since I couldn’t perceive any difference whether I was using the aid or not (no feedback, occulsion, loudness, or increase in clarity). So I returned the aid. The audiologist then recommended a BTE aid but I declined.
I have several relatives with worst hearing problems than I have and they all use CIC hearing aids which has proven to improve their hearing ability so I wondered why I didn’t find any improvement when using a CIC aid. Recently I decided give it another try but I want to be prepared before I see the audiologist so I’ve been investigating gain capabilities of different CIC aids incase that may make a difference.
I don’t think my hearing has decreased significantly during the past years (but I won’t know until I see the audiologest) but it seems that a hearing aid that uses a high gain concept in the lower input SPL ranges (0-50 DB) would probably not cause increased feedback since the peak output is still similar to other top of the line CIC aids (111-117 DB). If it was a problem, I suspect the manufacturer probably has capabiities to limit the maximum output via programming (compression algothrithm) since gain at lower input SPL DBs should normally not cause feedback. Because of my previous bad experience, I’m looking for an aid that has enough gain so that it can be adjusted so that I at least know it is working if I have a similar problem as previously.
Also it seems that an aid using a high gain concept may give better hearing results over an aid that uses a low gain concept. For example an aid that has a peak gain of between 35-45 DB (depending on frequency) would probably be more imbalanced trying to create a gain of 45 DB as compared to a high gain aid of between 50-60 DB (depending on frequency) peak gain. It also seems that an aid with a high gain concept may be able to produce clearer more balanced sounds (not necessarily increased db).
In other words if we assume my low frequency hearing is 15 DB, 2 kHz is 40 DB, and 3 & 4 kHz is 55 DB, you would think that a high gain aid should be able to easily amplify all frequencies to the same perception level without problems during the lower input SPL DBs (10-40 DB). As an example, if a 30 DB SPL sound was at the source, than no amplification is required below 2 kHz, 25 DB amplification is required at 2 kHz, and 40 DB amplification is required at 3 & 4 kHz to produce a perception of equal loudness at all frequencies. Once the input SPL approaches 50-60 DB, an imbalance would occur since the 4 Khz frequency could no longer be amplified the full 40 DB amount (see 60 SPL DB graph for Widex Inteo CIC and it indicates that only about a 30 DB gain can be generated at 4 kHz using 60 DB SPL). As the input SPL gets larger (70-90 DB), the imbalance gets worse where most frequencies 2 kHz and above will probably be amplified less than the theoritical desired amount (See 90 DB SPL graph where maximum gains are between 20 and 27 DB). So it appears that a high gain CIC should work well for normal communication but just like low gain CICs, will produce unbalanced results during louder sounds.
After investigating some more, it appears that most manufacturers use low gain concepts and have a compression threshold that kicks in at about 50 DB input SPL. When the compression threshold is exceeded, a compression ratio is implemented to reduce the maximum gain for all input SPL DBs above that threshold. The higher the input SPL DB, the more the max gain is reduced. However, it appears that the Widex Inteo CIC uses a high gain concept so its compression threshold has to be much lower, probably around input 30 DB SPL.
I suspect that the Widex Inteo CIC has implemented compression something like the following.
Everything below input SPL DB 30 has a max gain of 61 DB.
Input 30 DB SPL has a max gain of about 56 DB.
Input 40 DB SPL has a max gain of about 51 DB.
Input 50 DB SPL has a max gain of about 46 DB.
Input 60 DB SPL has a max gain of 41 (from graph).
Input 70 DB SPL has a max gain of about 36 DB.
Input 80 DB SPL has a max gain of about 31 DB.
Input 90 DB SPL has a max gain of 27 (from graph).
The above would keep any output from causing feedback problems that can't normally be solved by feedback circuitry.
The following is a link that describes compression.
The primary difference between high gain concepts and low gain concepts appears to be that high gain concepts can produce a high gain (approximatley 60 DB gain) that is balanced when only soft sounds are input (0-30 DB SPL) as compared to low gain concepts which will always (under all conditions) lose balance if the gain desired (needed) is greater than about 40-45 DB. I’m not sure how important that will be.
With only a 55 db loss in the highs, then 50 db of gain or more is absolutely not necessary.
The WDRC circuits do work and kick in at a lower kneepoint, usually around 45-50 db, which helps to raise soft sounds and lower down loud sound inputs. Pretty much every major manufacturer uses WDRC, although some manufacturers will give the audi a choice of compression schemes.
Thus, feedback should not be an issue, not with a 55db high frequency hearing loss.
If that is the case, you may also want to look at open fit hearing aids, as they are ultra comfortable and can utilize directional microphones, which CIC hearing aids do not have. In addition, cosmetically, they are just as un-noticeable as CIC’s.
I have to concur with Admin. It is completely incorrect to assume that a loss of 55dB requires a gain of 55dB to solve the hearing problem.
The hearing loss you describe can be addressed by many brands of CIC. Fitting a loss of this kind in this day and age is not a problem with the kinds of technology out there.
The biggest issue will be occlusion (the sensation of your ear being blocked by the hearing aid) and feedback. But with some of the modern technology out there it can easily be overcome. Starkey actually make a hearing aid that is pretty much feedback free, and has a massive vent making it effectively an open fit hearing aid.
Oh, and to answer your original question Starkey have products that can treat an 85dB hearing loss at all frequencies with a CIC and no feedback. So I doubt that Widex aid is as powerful as that.
I am doing that. Simply becasue in my country we don’t have good or professional audios. We only have hearing aids dealers who can make soem adjustments to aids ,but they aren’t professional. Each one sell one brand only, and each one wants you to buy from him. That’s why I have to make so much research before I go for any aid.
In additon, they will not give you trial period here. They suggest and aid or two for you, but you can take whatever you like. They don’t care. You will buy it and your money will not be returned if you don’t like it. It is an expensive decision.
The worse is that your options here are very limited. Widex, Phonak or Oticon are available here, but only few models of these aids only and not all.
I can only buy aids for one time and will can never do that for several years ,so I am not aided until now though I have sever hearing loss. I made a bad decision before and got Widex Bravo and now trying to learn from this. I prefer staying unaided rather than buying hearing aids that I will find out not suitable for me few weeks after.