All three of my daughters have bi-lateral steep ski slope shaped audiograms dropping down from 20db to 90db loss from 1000 to 2500 hz. My new audiologist (excellent) and another independent Sr. Audiologist (reknown) both said that we need many more mapping bands (15+ bands) then the hearing aids originally prescribed which had only 8 bands. I guess this ensures that there is no over or under amplification of sound in the critical part of the steep drop.
Q1. Do you agree with the audiologists that 8 bands total and only 2 bands in the key drop zone is insuffcient to accomodate this type of loss?
Q2. Which manufacturers and models would be appropriate? Right now we are looking at WIDEX Mind 440 and Phonek Naidia XI+.
Q3. Any thoughts on how I can get a refund on the others? Is someone regulating the HA providers
The answer is actually one channel to cover the lower frequencies and one to cover the transition. The Adapto instrument from years ago used to do this perfectly adequately with basically two channels and a variable crossover point combined with a dedicated ski-slope algorithm.
The resolution of the slope is nonsense, simply because the actual bands aren’t square, they roll-off at differing steepness either side of a peak value.
In addition, how do you actually ‘know’ there’s cochlear function above 1.5-2Khz? your children might only be detecting higher tones in this area due to the sensation experienced by the adjacent regions of the cochlear -which goes some way to explain why there’s such an increase of power needed over a very small change in pitch.
Management of this kind of loss would suggest that frequency transposition (Phonak but not the Naida - something less powerful) may provide a better frequency range (in time). Although you might equally want to consider that basic hearing aids with all response removed above 2Khz may provide an equal and more acceptable solution without issues of feedback. The reason for this approach is that when your Naida dumps the level of power it needs to compensate for the HF loss, it effectively kills the properly heard portion lower down. In addition, the actual resolution of what is ‘heard’ at 2Khz may be incredibly poor, thereby further reducing the ability of the brain to decode speech.
With severe problems like this I would recommend that your children take a TEN test to accurately identify dead cochlea area’s. Unfortunately few Audiologists are using this test. Ed
Bands = fixed frequency range where volume is controlled
channel = fixed frequency range where compression (and volume) is controlled
But the above 2 terms are used interchangeably. audiophiles and the world i believe use bands to mean channels too. and really bands is the correct term. channel is just what we hard of hearing people use to try to separate aids that do not adjust compression but changes the volume for certain “bands”.
yes, the more CHANNEL’s the better. phonak is known for selling 20 channel aids. the rest of the top tier manufacturers, Siemen, Oticon, etc. sell 15 - 16 channel aids. More channels make the aids sound better. but most can’t tell the difference between a 15 channel aid vs a 20 channel aid.
However, it’s probably better to focus on other things such as the fm support for the product. Phonak has extensive fm accessories that can help your child hear in classroom situations. Technically they can be used with other aids but probably will not work as well.
nadia is a great choice as it’s the power aid of choice today. mind is also a great choice. widex and phonak use different approach so these are good aids to compare.
when you trial aids some audi’s let you try multiple aids. you don’t refund the aid. you try them out for typically 30 days. the only catch is that most will charge you a fee if you do not purchase an aid. Like $300. Good audis let you trial for 60 days but this is very rare. However, I find that most people just try out one aid and most audi not surprisingly encourage that.
If the audi you have do not have the mind or nadia aid then I suggest you try out an oticon aid. The oticon sumo is famous for the being the old king of the power aids.
Just the bits highlighted above, there’s fairly extensive evidence that anything more than seven or eight channels is a pretty pointless exercise in terms of most people’s hearing. In fact when you break-up the sound further the risk tends to be that you introduce more processing delay, quantization errors and temporal distortion artifacts. However, the fact that it’s not that necessary doesn’t tend to affect purchasing decsions of five litre cars, so why should it affect hearing aid sales.
Please don’t assume that these kids require a power system for a ski-slope loss. Your loss may require a power aid. The pathology of the patients in this case isn’t necessarily the same.
Just a small NB: It was Phonak/Unitron who started mixing channel and band notation a few years ago, but I’m sure they weren’t the only ones.
When you say the Naida days will be over in about 3 weeks what do you mean? Is there a new model coming out.
Also do you think Phonak’s frequency compression is better then WIDEX’s frequency transposition?
Thank you all for your informative advice. It really is overwhelming trying to decide for 4 year old twins who can give limited feedback on which is better to them.
There’s a new phonak platform out called Spice. It will offer an enhancement to the existing product line. We’ll be seeing the UK launch on 22-23 of this month.
The frequency compression technique used by phonak seems to work better than the transposition in the Widx aids.
This is a great thread. Um bongo is all over what I have experienced.
I have used only Phonak aids, the Savia 111, Nadia V SP, Exelia Micro and the Exelia Art M. This experience is based on me doing the programing, not an expert by any means.
When ski slope hearing loss is talked about many users want powerful aids to compensate the high frequency loss. I have found less power to work better for me. The Nadia aids were plenty powerful to hear high frequencies but speech was lacking. Now that I use the Exelia aids my speech comprehension has gotten much better. I enjoy music again!
Thanks to all the pros and members here for guidance and help I now hear better than ever expected.
I meant in about 3 weeks Chili will be out and the days of Naida will soon be over.
The difference between Phonak and Widex is that Phonak uses frequency compression and Widex frequency transposition. AVR sono has been using frequency compression for a long long time…
This is my fear with the kids, power aids and the ski-slope loss: the ‘downward spread of masking’ is likely to be a major problem AND they won’t be able to respond in a way that will tell the dispenser/parent anything meaningful. Long term, the potential is that you could turn them into sound junkies as they will always be looking for a noise floor even in the good portion of their hearing.
There’s two other reasons why the ‘less is more’ approach would be beneficial - the first relates to canal volume and over amplifying the lows inadvertently. The second is feedback and general acceptance of the aid. If you get an aid tuned to this loss with a properly fitted mould, in three months it will be loose, in six it will be constantly whistling - this is likely to make the child less happy to wear the aid. (Usually they put them in with the battery out).
Thanks for the plaudit BTW. It’s nice to put the experience to use sometimes. If you could mention this to a few of my potential customers…
Just add one comment about marketing aids to a mostly non-technical public. More is better they think. 20 channels must be better tnan 8 or 15. Ain’t so,
Also breathes there a busy audiologist that has time to accurately program 20 channels? Most simply use the software to set the parameters. Ed
English: One simple fast and low cost trick I think works is to take a constant output audio signal generator and see if the patient registers a sense of change of pitch as you go up or down in frequency.
Dead area’s are the frequencies where there is no perceived change of pitch…or no response with the same level volume.
Don’t up the level or you’ll get a false responce due to recruitment. Try it. Ed
Err, wasn’t the question; how many bands do you need to deal with a ski-slope loss. As I pointed out, it is two with a variable crossover. Anybody who’s built a speaker set will know this.
As for your contention about the efficacy of the downward spread of masking, the recent lecture from Mr. Deadspot - the guy we were talking to in the bar with Roger - remember what he alluded to about the function of the basilar membrane under HF stimulus; in effect it would give a flattish response for low frequency even when the sound was being ‘heard’ across the hf range.
I concur that the upward spread of masking is a greater issue under normal conditions (lower louder sounds do block out sharper speech), but by how many times is power increased across the ski-slope we’re discussing: 1000x ?
So would an Oticon Pro Vigo with only 2 mapping points in the steep ski slope drop amplify the sound effectively is my question? As a laymen, I am not sure what a variable cross over is but the Sr. Audiologist at Oticon did not describe to me a different amplification at the mid point of the drop. In other words it potentially could over or under amplified.
Yes it would, with one caveat. If your loss falls off more steeply than the bands of this - or any - aid, it may prove difficult to map accurately. I you doubt that the aid is performing as it should, get them to do a speech-map to identify what’s happening.
