The SoundRecover frequency shifting and sound quality

The soundrecover by phonak compress and shifts high frequency sounds to lower areas. I wonder how it affects the quality of shifted sounds ? I mean if they sound the same or there is a quality change ?

As I understand the feature, without it I would not hear anything at the higher frequency at all.

My question is whether anyone else makes a hearing aid with a similar feature (but know by a different name).

I believe Starkey does something similar called Spectral iQ for those who need the feature. It is available in the X Series and Wi Series aids.

ZCT can provide more detailed information.

I have Soundrecover on my Phonaks and it is quite transparent to the user.

For me, the compression starts at 3K so anything above that is compressed into a narrower band. 4K moves to 3.5K and 8K moves to 5K etc. It’s like taking an extended spring and compressing just the top part of it whilst leaving most of it alone.

If the starting point is set too low then it produces a weird sound because you are overlaying the compressed frequency on top of a frequency that you can hear naturally.

It definitely helps to hear the consonants in female speech.


It just compresses the frequencies, it doesn’t shift them. See Gilbert’s post above, it is the experience that I get from most of my patients wearing Phonak’s hearing aids.

I do use soundrecover and I have a feeling that I hear high frequency sounds a bit ‘lower’ or less pitched . I can hear high frequencies without soundrecover but I chose it to extend my frequency range up to 8500 hz. But I feel a slight change in quality when listening to music.

I believe the premium starkey and widex aids are the ones that shifts sounds to lower frequencies. This is called frequency transposition.

Phonak just compresses all sounds above a certain threshold, compressing them into a smaller frequency range. Phonak avoids having to deal with sounds overlapping.

Impact AVR (part of sonovations) did something similar but they compressed all sounds. They were however the first to manipulate frequencies. Phonak and Impact technology is sometimes referred to as frequency compression.

But many of these companies mix up the label “frequency transposition” with “frequency compression” just like some mix up the term channels and bands.

I confess I have just begun to look, but I have been looking for that specifically and other than Phonaks have not seen it mentioned.

The best I can understand my hearing dB loss chart, the numbers are:

Freq L - R
250 10 - 10
500 20 - 20
1000 35 - 40
2000 35 - 40
3000 55 - 60
4000 60 - 65
6000 65 - 75
8000 75 - 85

I wonder why they keep it such a big secret? My audiologist told me many people have my ski slop shaped chart and seemingly many could benefit from this with respect to high frequencies.


Phonak bang on about it at every opportunity they get. However, it’s one of those features that requires you to have a bit of understanding about your audiogram and I guess that’s beyond the scope/imagination of most of the advertisers out there, so it doesn’t always get a wider audience.

Your audiologist is quite right.

Sound quality is not a key issue with Phonak Sound Recover.

You have probably not heard the shifted items for 10 or more years so you have forgotten the ‘true’ sound.

There are a couple of exceptions:

  1. Users who have suffered a recent HF loss. They can remember the ‘real’ sound and so can be annoyed by the ‘new’ sound.

  2. The 1-in-1000,000+ people who have ‘perfect pitch’. They can hear exactly what the aid is doing and this can disturb them.

  3. Those with one good ear and one poor ear. The good ear can hear the ‘real’ high notes whilst the downshifted notes arrive in the worse ear. This mixture will sound terrible - such users are NOT candidates for frequency shifters.

And of course to be a candidate for Sound Recover you need to have a severe high frequency loss, and yet still have some hearing at around 2kHz - 3Khz.

sorry got to change what I’ve wrote about the starkey aid. They actually copy the sound to the lower frequency while keeping the original high frequency sound. I still consider this frequency transposition.

I hope nobody is using this feature as a deal breaker for choosing an aid. This is more of a nice to have feature as I have never read about anybody considering this a must have feature. but then again I’ve read about audis claiming huge success with people with very ATYPICAL (not ski-slope) hearing loss as implied by EnglishDispenser’s post.

Based on my audio-gram, would I be a good candidate for frequency shifting on the Phonak Audeo Smart S IX line?


FWIW, Widex calls the feature “Audibility Extender.” It does a “move” not a “copy and paste” (like the Starkey).

Can’t post a link. Google “widex audibility extender.”

I’ve been trialing the Clear 440. The audibility extender is actually a distinct program - it’s not an automatic feature of the master program. A Widex rep (whom my audiologist invited to do my initial fitting a week ago), declined to load that program, stating that my specs suggest I don’t need it.

I’ll report in due course on my experience with the Clear 440.


Here’s a link that proved to me that widex was transposing the sound wave to a lower frequency. my jaw along with many others dropped when we realized it was not just compressing sounds.
but this feature never panned out as well as we hoped. I was hoping one day phonak would take a shot at this but with all that they invested in sound recover I doubt it.

And here’s an amazing product for bird watchers that gives you sample audio and I think this is a good example of frequency transposition. songfinder

I would say yes. The poorer your high frequency hearing is, the more likely you are to have cochlear dead zones. This usually translates into reduced clarity of speech/poor word recognition scores. In my experience, these are the types of hearing losses that can benefit most from Sound Recover (and the types of losses they are intended for). Of course, I like the Phonak HA’s for just about everyone…lol

Thank you for your feedback. I can;t wait to get my Audeo Smart IX’s

My Agile pros do sound really great, but they seem to not have the volume I need without feedback issues.

So… since I’m qualified for number 2 and 3 of your description here… do you have any idea what are other options? It drives me CRAZY to hear things not where I know they should be. It’s getting better, and I’m learning to ignore the occasional cross-tones when I’m working (I’m an x-ray tech… so between the beep of the machine when we make the exposure, to the various beeps and chirps of monitoring equipment in surgery, I get a lot of tone-specific beeps) but other times it’s … disturbing. :smiley: Thanks!

Why Smart IX and not Naida with as big a loss as you have? I would think if you are already having trouble with pumping lots of volume that the Naida SP or even UP would have more power to deal with covering your needs? They both have sound recover and are water resistant. I think the SP now even comes in a CRT model.


Mkah, Keep your expectations low. I have a similar hearing loss to you and just trialed the Wi, Ambra, Agil Pro and Clear.

For my hearing, the Agil Pro and the Wi have FAR superior sound quality to the other two.

Clear - Audibility Externder is a very odd - in essence, it seems to elongate soft consonants - turning a sh into a shhhhhh; weird. The Clears seem to pick up artifacts with loud music. I did not like them.

Ambra = The Ambras work well in most environments at pulling in the speakers voice and shutting out other ambient noise but have just awful sound quality - they sound like transistor radios. I am not alone in this latter opinion.

Wi - The Wis were excellent in almost everything but awful in noisy scenarios. If those work for you in noise, that may be the best hearing aid out there.

Agil Power Pro = My Agil is a Power Pro and it has plenty of volume. That may be why I don’t need more power even though my loss is worse than yours. The Agils have very good sound quality and are almost as good as the Ambras in noise. They are no fuss as they only have one main program for noise and quiet and they can toggle up and down between other programs.

It took me several monts to get used to sound revocer. At first, I felt that sound quality changed . It felt like some high frequency sounds were thicker than usual and human voices were of more high pitched. Over time I got used to it and sounds seems more natural. Type of hearing loss and brain are important factors. The brain needs time to adjust to shifted sounds. I need more time than most users . I guess it took more than six months to fully get used to sound recover. It was worth time.