Friday, July 24, 2009

Getting some facts straight regarding audiograms, hearing loss, HAs and CI.

Someone said to me: I learned something at JTC I thought I would share with you.

(you showed me the image)

Do you see that triangle at the top of the audiogram? You hearing aids should be programmed inside that triangle for speech perception. If they aren't able to reach that high, they need to be, at least, shaped like the triangle. Low frequency sounds like "ahh" and "b" are much louder when produced than sounds like "th" and "f", so they need to be amplifed LESS than the high frequency sounds. If they are louder, they will overpower even more. Your audiogram should ALWAYS slope UP, even if that means that you need to amplify the lows less.

Also, the line at the bottom represents the WORST your hearing can be and still be aided into the speech banana.

Caution: This is only true if you are seeking the ability to understand speech through audition.

It's impossible to get to the triangle(25db HL) in the high frequencies. For that ill need the transposition cutoff to be closer to 500Hz than 1500Hz. Maybe Phonak will design a new HA where the transposition has more programmable options. With a 1500Hz cutoff, I pretty much don't benefit from transposition since I have 120db loss at that frequency.

When my HAs were reprogrammed, different aided results were tried and with the gain on the lows reduced, I heard less. My parents said I begin to talk too loud and they had to shout at me so I could hear them. My ability to understand speech dropped as well. I also was missing out on some environmental sounds with less gains. So yea it's always good to give as much gain as possible, why hear less?

As for the bottom line(black dots) that's not true! Look at the 750Hz, 1000Hz and 1500Hz results. It's a matter of getting the most powerful HA and correctly programming it for the best possible aided hearing. I am sad when I see people with better unaided hearing than me hear worse than me aided. They need better HAs and more amplification!


Levels of Hearing Loss. What's the difference?

(note: I had to correct some of the grammar. Whoever wrote the guide below needs to go back to school)

Mild Hearing Loss(25-40db unaided, 0-10db aided)- a child with mild hearing loss usually has normal speech, but will have trouble in the school setting because it will be difficult to hear speech from more than 12ft away or when there is background noise. This is because much of the meaning in English is contained in the voiceless consonants which are high-pitched and soft. They are s, sh, t, p, k ,f, ch, and th.
A child with a mild loss in both ears will need some amplification in each ear to hear clearly at school , in groups, or at a distance.

My comments:  Makes sense. People who get a CI on average end up hearing 25-40db aided. So I want to make it clear that a CI does not cure your deafness nor does it give you normal hearing in the large majority of cases. You will hear equal in quantity to someone with a mild hearing loss after CI. Someone with a mild unaided loss should be aided to 0-10db with HAs. Low power, open fit HAs can do the job in this case and will give you normal aided hearing.

Moderate Hearing Loss(40-70db unaided, 0-10db aided)- a child with a moderate hearing loss can clearly hear speech only when the speaker is very close-less than two feet away. They need hearing aids to hear the softest sounds and to acquire understandable speech. If they receive hearing aids before four years of age, they usually progress rapidly in learning to talk.

My comments: Powerful HAs can aid a moderate hearing loss to 0db and no worse than 10db. I have a 55db loss at 125Hz and am aided to 0db. At 250Hz, my loss is 70db and im aided to 5db. There's still enough residual hearing to hear normally and even get to 0db.

Severe Hearing Loss(70-90db unaided, 10-30db aided)- Children with a severe hearing loss do not perceive speech no matter how close they are to the speaker. They will not learn to talk clearly and be understood without hearing aids or cochlear implants (70db or worse across the audiogram should consider a cochlear implant). All children with a severe hearing losses require special help because they receive only a portion of the clues usually available in speech sounds. With hearing aids they can detect vowel sounds,pitch,some consonants, and stress clues from speech. With their eyes they can learn to detect about 25 consonants sounds. With lipreading and listening together, they may receive about half of the clues that normal hearing people use to understand speech.

My comments: While severely deaf people experience a silent world unaided, they can be aided to normal or near normal with powerful HAs. A CI is not a wise option when powerful HAs can aid a severe loss similar to what a CI can aid. I have friends with a severe hearing loss and with the right HAs, they hear/understand speech(including S and F) as good as a CI. 

Profound Hearing Loss(90db+ unaided, 30db+ aided)-

Children with a profound hearing loss receive even less auditory information. If the child is under one year of age, they are too young to get a cochlear implant. In most states, the child needs to be at 9-12 months old. Hearing aids are not going to give much to a child with a profound hearing loss. Example: A child wearing hearing aids with a profound hearing loss will hear the sentence "Go get your shoes" as "oh eh yoo ooh" If you have dreams of your child talking and speech sounding very clear, then hearing aids are not an option for a child with a profound hearing loss. Remember 70 db or worse across the audiogram. Match the technology with the hearing loss. No Hearing aid in the world will help a profound individual like a Cochlear Implant will. 

My comments: This is only half true. I was born profoundly deaf for the most part and my old audiograms show a 100db HL at 1000Hz and higher frequencies. I was still severely deaf in the low frequencies with a 70db HL at 250Hz. I had to make do with analog HAs as well. Someone today would hear much better with powerful digital HAs.

They can still get decent benefit depending how profound their loss is. I was able to talk/speak clearly and hear/understand some speech as a child. I had much worse than 70db in the mid/high frequencies, try 100db! Not only that, I did great with old analog HA technology. Today's HAs can give good aided results for hearing loss as profound as 110db and have fitting ranges as high as 120db HL!

There's no guarantee if you have residual hearing that youll hear better with a CI, especially if you have plenty of residual hearing. CIs are great technology but should be considered a last resort after you have tried all the best HAs programmed with maximum gains. As for understanding speech, most deaf people are great lip readers and combined with sound awareness, they can score around 90%. Many of them also use sign language as a means of communication. There is a $50,000 cost(sometimes paid for by insurance) for CI as well as many risks including surgery itself.

I am not against CI but realise there is way too much hype surrounding this technology. Ive read many CI blogs and alot of people have unrealistic expectations. They claim that they will(as in 100% chance) that they will hear perfect or at least much better than with HAs. I hate to say this but there are no guarantees with CI or any other technology. The more residual hearing you have, the more you will benefit from HAs. I get great benefits from HAs(at least in the low frequencies) and if you have equal or greater residual hearing than me, you will hear more/better/louder with the right HAs than I can. Go visit your audiologist and get your HAs reprogrammed like I did, you will thank him and hear much better.


  1. I think you are wrong. You don't hear better with transposition hearing aids. It's distorted sound.

    Also I doubt that very few who have CIs are expecting normal hearing. One of the criteria for acceptance for CI surgery is that you have realistic expectations. The informed consent for the surgery makes it certain that you will know what the worst case scenario is before you have the operation.

    I wanted better hearing than I could get with HA. Less than 2 weeks after activation I already have that. I can hear sounds I haven't heard for years, i'm sure there will be some sounds that I have never heard.

    My life is already better because of my CI, no hearing aid has ever given me this ease and comfort in hearing.

  2. I don't know much about transposition. My own HAs have transposition but the cutoff is 1500Hz. My hearing loss is 120db at that frequency and I might have a cochlear dead region anyway. I don't seem to get any real improvement in speech above 500Hz. Id need a HA that can transpose down to 500Hz.

    I don't know what distorted sounds are like since ive always heard like that and have nothing better to compare it to. But I read that the worse your hearing, the more distorted sounds will be.

    Didn't you have near normal hearing in the very low frequencies? I am not even sure if CI can give me what I hear with HAs in the lows. My home test shows I hear about 5db aided in the lows.

    Did anyone give you the percent odds of CI giving you better hearing than you could get with HAs? Ive read around and from what I know, my odds are 75% of hearing better and that's with a starting loss of 70db at 250Hz.

    I mean, I might hear sounds with CI that I can't with HAs, but there might be sounds I can hear with HAs that I can't hear with CI. I already seem to hear some faint humming/rumbling sounds that some hearing people can't.

    I am happy CI works for you. I made a thread about CIs just now. There is so much I need to learn about CIs, hope you can share more information. I thank you for your time.

  3. I agree to this one..

  4. I am also very happy for that CI works on you. I wish that you will be more better. I think hearing loss is just part of that sickness.

    hearing loss

  5. These facts are very important and I am so glad that I read it in your blog. I will be visiting this blog for more post just like this.