Phonak Marvel - vibrating tremolo effect for high pitched (electronic) sounds

@uburoibob said:

Shutting off the ‘whistle reduction’ (the feedback squashing algorithm) is what gets rid of the tremolo - but of course, then you are subject to a lot of feedback.

@uburoibob said:

The problem is the aid recognizing higher pitched pure tones as feedback and then hopping into anti-feedback mode. Coupling will not make a difference.

Sure it will. It will allow you to turn off the whistle reduction in all programs, which is what you say is causing the problem.

You may run into occlusion issues on the other side, though, which could be worse. But individual sensitivity to that varies.

What I was going try next was exactly that - shutting off Whistle Stop in all programs. I can live with the amount of feedback in the music program - no big deal. The person at Connect Hears knew I wasn’t going to be purchasing there, and I didn’t really want to put her through any more stuff just to buy them at Costco. So, I decided to wait until I get to Costco to experiment with shutting off Phonak’s feedback rejection system completely.

Still, seems to me that if one HAS to hear that trem/trill effect when it’s engaged, it’s a faulty design, right? So, for me, I’d prefer to not go full-bore and block out the lovely natural bass that I hear just fine in order to overcome what seems to be a design flaw in Phonak’s hearing aids.

@uburoibob said:

Second, REM with the Marvels is accomplished by a mic in the Marvels and audio generated inside the aids by the programmer - so there is no provision for REM clinically to measure audio that’s picked up by the Marvels’ mics in any meaningful way (in particular, the pure tones that trigger the trem effect).

My understanding of a real REM test is that it could be done on most any hearing aids. However, the question would be whether or not the pure tone signals could be displayed in a manner that would show what the waveform looks like. The purpose of REM is to get the sound amplitude vs frequency correct. You would need an oscilloscope type display that locks on the wave form to see what else is there.

@uburoibob said:

Still, seems to me that if one HAS to hear that trem/trill effect when it’s engaged, it’s a faulty design, right? So, for me, I’d prefer to not go full-bore and block out the lovely natural bass that I hear just fine in order to overcome what seems to be a design flaw in Phonak’s hearing aids.

Is it faulty design? Or is it an effective way of dealing with feedback in situations that might warrant it? I have a pair of marvels and a pair of opns on hand, and right now with the settings I’ve got I can’t get the marvels to do it while the opns are doing it pretty strongly. (They are not set up identically.) Whether it is there would, I’d expect, depend on the feedback risk given the individual gain and acoustic set-up.

IIRC, most manufacturers use some sort of pitch shift or phase delay for their active feedback management. I’m not actually up to date on how the fancy new opn s feedback managment is supposed to be working (were’s volusiano).

REM microphones and test signals are external to the hearing aids. That’s the whole point. However, the measurement is averaged over a relatively long time window. Too long for what you’re looking at.

I’ll admit to not being a pro, but I’m pretty sure there’s no microphone in the Marvel’s receivers. Receivers for all intents and purposes are replaceable speakers and there’s no purpose for having a microphone in them. Microphones in the Marvels sit in the body of the hearing aid. Phonak may have some way of simulating REM, but “real” REM uses a separate microphone placed in the ear.

@uburoibob said:

I’d say that there’s something flawed in the process. Whether it was the Phonak technician who fitted me while on the phone with Phonak, or it’s the current version of Target fitting software, or the aids themselves, I don’t know. But I do believe it can’t be right.

I agree. As I’ve already mentioned, I currently have the Phonak Nathos Auto and Oticon Dynamo SP8. The Phonaks warble, the Oticons don’t. I’ve previously had Siemens aids and they’ve never warbled either. Hmmmm…

Sounds like they ran the in situ audiogram for some odd reason, not REM. Shouldn’t make much difference with the trouble you are having, though.

I’m an audiologist, so yeah I do set things up on my own. But I don’t have much of a hearing loss and what I do have is a bit atypical, so while I do like to test drive things my experience is not going to truly be comparable to typical users.

I have been following this thread some wondering what could be done to fix this tremolo effect.
I have an app called Spectroid on my phone. It monitors frequency and decibels. If someone could play the piano or guitar to find out exactly what frequency this tremolo is happening I wonder if lowering the gain in that particular frequency could stop this tremolo effect. Just a guess but trying to help.

BTW, I had the WhistleStop turned down from 8 to 4, and although a little better, I can still hear the effect. I can even whistle myself and hear it, especially if the aids are turned up more.

Exactly. And the more you notice it, the more you notice it.

Dave, if you are full-in with the Phonaks, your audiologist/fitting technician can create a manual MUSIC program for you. Just have them reduce WhistleStop to zero. That will eliminate the Trill effect. You aids will feedback in the normal situations (hands close to ears, etc), but they sound very good that way. Problem is, when you go back to Autosense 3.0, normal everyday stuff still trills in the higher frequencies.

And to clear it up - looking at the user manuals for Phonak’s target software, they don’t do REM within the aids as I was told - it’s something they call “Real Ear Test” where they play a range of tones that, I presume, set the comfort levels for Sound Recover, WhistleStop, etc.

I am a performing wind musician. I used to get this this “trilling” sound when playing. I once heard it described as the sound you get when “playing into a fan”. To eliminate this on my Phonak hearing aids my audiologist turned off the the feedback manager on one of my programs so I could perform without this trilling sound. When I changed to Widex a couple of years ago we had to make no such adjustment.

Thanks for the feedback. I will be seeing him this Sat and will see what can be done. Maybe going the manual route is the only way.

I can see feedback happening if you place your hands too close to the aids. What else will cause this?