Can Hearing Aids Cause Vocal Fry?


#1

I’m five days into using HA’s for the first time. One whole, I thinking I am adjusting fairly well to it all. I do have an issue with distortion in the left hearing aid at certain frequencies at higher amplitude, but if anything it seems to be reducing. The other issue is somewhat intermittent, and it is at least a perceived distortion of voices including my own at times. They did the Own Voice calibration and that did help a lot. But what I am hearing is certain voices, mainly female taking on a “vocal fry” sound. Here is what I mean by vocal fry:

Vocal Fry - You Tube

Some people put the effect on, and I think in others it is somewhat natural. But, I am hearing a lot of it now compared to what I heard before HA’s. I guess that could be part of just hearing what was always there, but I was not hearing. Or, I also wonder if it is a “distortion” effect caused by the hearing aids. Vocal fry is basically a lowering of the speaking voice frequency. I have substantial high frequency loss and I am now wondering if the hearing tech possibly turned on or adjusted the bandwidth compression feature in my KS8 HA’s. Has anyone that is using frequency lowering or bandwidth compression experienced this effect? What is somewhat annoying about it is that it kind of comes and goes and seems to be somewhat sensitive to my head position relative to the source of the voice.


#2

Sounds odd to me. Most people with high frequency loss complain of things sounding tinny or lispy. Did you get a look at your fitting or REM? Should be pretty clear from that if they used frequency lowering (Bandwidth Compression). I wouldn’t think they would , especially if they used the inexperienced setting. Also your right ear isn’t that bad and Connexx bases settings for Bandwidth Compression off of the better ear.


#3

I kind of got a look at the fitting process but I believe she was using the Aurical software to do the REM fitting. It was a screen with a whole bunch of curves that I did not get enough time to figure out. If she did the downshifting of frequencies, I believe it is part of the Connexx, Fine Tuning, Bandwidth Features, section of the software. From what I see of it, it adjusts both ears, unless they are unlinked. I will have to just ask her at the follow up fitting to see if she has done it.

Based on what she told me the HA’s were set up to the Experienced SmartFit prescription and then checked and adjusted to the NAL-NL2 Experienced.

If she did not use Bandwidth Compression, then I am left wondering what is causing the effect…


#4

It does adjust both ears, but default is to adjust to the same frequency compression level for both ears. As much as possible I’d try to focus on are you understanding speech better rather than sound quality.


#5

You have a very steep loss curve in your left ear. I have a pretty steep loss curve in my right ear as well. It may very well be simply distortion on the left receiver because it’s undersized and overdriven, if it’s not a defective part in the first place.

I’ve had to replace my right receiver due to distortion already after a while, while my left receiver is still working OK.

What size receiver are you fitted for your left ear? If it’s an 85dB receiver, then it’s borderline on your high frequencies and can be overdriven.

When I put my right receiver to the max amplification allowed at the high frequencies, I don’t really hear the amplified high sounds, but instead I only hear the lower frequency mechanical buzz sound of the receiver because it’s being driven so hard, which I have no trouble hearing at lower frequencies.

I concluded that my high frequency loss is long gone with dead nerve area there already, so I give up trying to amplify them at those high ends anymore. I model my audiogram to show no loss at the regions above 4 kHz just to eliminate the mechanical buzzing sounds generated by the receiver when being driven too hard at those high sounds. It’s something you can try to at least see if the “frying” is eliminated if you do that or not.

I use frequency lowering to move those high sounds down to the 2KHz region so I can hear those high sounds. I don’t know what hearing aid model you have, but mine is the Oticon OPN, and I have an option after I transpose and compose the high frequency sounds into the 2KHz region, I can simply turn off amplification at the high regions (or leave it amplified, whichever way I choose). I choose to turn it off because like I said, I think the sounds in those high frequencies for me a way long gone so there’s no point in amplifying them anymore.


#6

I am using the M receiver on the KS8. According to the spec sheet I should be well within the power capability.

image


#7

Like I said, I’d suggest trying to turn off amplification at the 4KHz range and up on your left hearing aid next time you see your provider just to see if the “frying” goes away or not. If it does, then it’s due to the receiver being overdriven to the point of distortion at the high frequencies. If it doesn’t go away, then you can always restore it and at least you know that it’s not a distortion issue at the high frequencies.


#8

I wonder if you could just ask your provider for a printout of the equivalent of the Clinician’s Report, then study it, or offer info from it to get help from others here. With ReSound the Clinician’s Report from the Smart Fit software is very detailed, program by program, as to the exact settings implemented by the fitter. Hopefully the fitting software used for you offers the same options (with ReSound, the fitting can also be saved as an XML backup file and restored to another copy of the fitting software program but perhaps your fitter being associated with Costco and its institutional correctness would not go so far as to let you have the actual fitting “data” in electronic form).


#9

I see that the Connexx 7 tutorial says the software applies bandwidth compression automatically if it things it is necessary. With my audiogram in the Connexx 8.5 software I don’t see that it has applied anything. It would seem it could only be there if the fitter thought it was necessary.


#10

I did an online test without HA’s and got no noise or buzzing at the 80 dB loss signal level for the higher frequencies (no hearing either). I repeated the test with the HA’s on using headphones and right across the high frequency range at the 80 dB loss level I still get no buzzing. I have some audibility at 4 kHz, but nothing at 6 and 8. It is puzzling…


#11

I am using Connexx 8.5 for simulations, the same software as the fitter. Yes, she can give me a PDF printout that documents all the settings. And she could also do a database export of all my data. I don’t think I will push her for it, yet. I will try and work with her for now, but I will question whether or not bandwidth compression was applied, and whether or not the left receiver could be defective.


#12

I’m in the same boat. I get no audibility at 6 or 8 KHz. I just attribute it to being too far gone (dead region of hearing). There can be various reasons why you don’t hear anything at 6 or 8 KHz:

  1. Your headphones (I assume that’s how you do your online test) is not driving the 6 and 8 KHz test tones hard enough.

  2. Even if it does generate the test tones, there’s a possibility that the level of amplification programmed into the hearing aid is not enough to be audible to you and surpass your left ear hearing threshold at these 2 points. It may be that your 6 and 8 KHz zones are already your dead region, too far gone.

  3. If there’s no buzzing noise heard at 6-8 KHz, it may be that:
    a. The receiver is not being overdriven enough to cause the buzzing noise like my receiver, in which case that is good.
    b. Your (mild) hearing loss at the low frequency (wherever the buzzing noise occur) is not sharp enough to hear this faint buzz, in which case at least it’s still a blessing that you’re not picking up this sound.

I would still try to avoid amplifying at 6 and 8 KHz if you already simply can’t hear anything at that level of loss. It’s just a moot point trying to amplify those 2 points to max level if you can’t hear sounds there anymore. It can only increase the chance to overdrive and distort the receiver at other frequencies. If anything, if even turning off amplification at those 2 points doesn’t help solve the “frying” issue, you can always restore the amplification there later on if you want, regardless of whether you can hear it or not.

Another thing to consider is that max’ing out the amplification at the 6 and 8 KHz data point may increase the chance for feedback at those frequencies. If feedback happens there, and you can’t hear that high anyway, you may be unaware of the feedback, but it may drive normal hearing persons next to you crazy. My mom was very hard of hearing and her hearing aids used to feedback all the times, at the frequencies that she couldn’t even hear herself. So she totally never knew that her hearing aids were giving feedback unless it bothered my dad and he told her so.


#13

From the playing around I’ve done, I’d really be surprised if you had bandwidth compression. I think Costco fitters are loathe to use it unless the software tells them to.


#14

I went back to the Hearing Instruments selection page which shows how my specific hearing loss fits the chosen M receiver. Here is what I got. I see the right ear goes outside the darker gray blue fitting range. Could that cause any issues?

Here is what it would be with the S receiver.


#15

I don’t see how it can. I think the right one going outside the gray area simply means that you’re not going to get more than 1x amplification at those points. But I would think that it should reproduce the sounds at those frequencies just fine.


#16

If it was me I would stay with the M receiver and apply gain overall. 90 db loss is bad, but it’s not dead. You may or may not hear feedback at those frequencies, and the KS8 doesn’t have the best feedback control, but it may be good enough with a good fit.

You are hearing distortion because you are sending sound to a 90db loss frequency and your brain hasn’t heard that. You can leave it turned up and see if your brain eventually sorts it out (mine did) or you can turn down 4k+ frequencies.


#17

Thanks for the comments. I think I had a bit of a breakthrough tonight. It was 5 days and 5 hours since I got the HA’s put in and my left HA battery went dead. I was watching a TV sports game and didn’t bother to change it. The vocal fry went away with only the right HA working. I was not hearing the vocal fry of my own voice either. The listening experience with only the right HA working was the most comfortable and clear sound since getting them!

I think whatever the problem is, it is only with the left HA. I will do some more testing tomorrow with the tone tests. It would seem that some tone at a high amplitude should produce the noise/distortion that I am hearing.


#18

I did some more testing using an on line test site. Here are the results using headphones while wearing the HA’s. I would say the test results are about 5 dB optimistic as I wanted to be sure I could go through the whole frequency range. I did hear the higher frequency 6 and 8 kHz but just barely. I did not hear any funny noises or static, just faint test tones. If there is any frequency that did not sound quite right, it was the 2 and 3 kHz test tones. I suspect this test is not very accurate at the higher frequencies because sound gets quite directional as the frequency goes up, and the microphones on the HA’s behind the ear are not ideally located inside the headphones. Suspect the real test results would be higher if the speaker and microphones were better aligned.

Here is what I got with the same hearing test without hearing aids. In this test I would expect the higher frequency results to be more accurate.


#19

Do you hear the vocal fry when listening to audio from video or audio contents from your computer using headphones?

If yes, can you isolate the left and right audio to confirm that the vocal fry only occurs on the left hearing aids?

Then, can you find some kind of audio equalizer app for your computer and try to play around to see if you can isolate the frequency regions where the vocal fry occur? For example, turn down amplification in the mid and treble first and listen for the vocal fry (assumably on the same audio content in which the vocal fry occurs) in the bass area. If not heard there, turn down the bass and treble and listen for vocal fry in the mid area. Then finally turn down the bass and mid and listen for the fry in the treble area. At least, this is one way of isolating the trouble area.


#20

To me your results seem pretty reasonable. I’d say it’s pretty clear that frequency lowering wasn’t used. The right ear gives you solid hearing out to 6khz and audibility to 8khz and the left one audibility out to 3khz. Seems like quite an improvement. Don’t know what to make of the strange sounds your getting. I’d mention it to the hearing aid fitter, but I’d try to focus on the improvements instead of the problems. It’s amazing what one can get used to.