Hearing Aid Feedback

[Harold Bullard]

I'm sure this topic has been addressed before. I've done searches but couldn't find it. I though it couldn't hurt to start a new thread.

One of the singers in my band wears hearing aids. When he begins to sing he very often gets feedback from the microphone. (high pitched squealing; you guys know what I mean) It's my understanding that several things could be at play.

He uses a Shure Beta 58 (directional/cardioid)which is supposed to have feedback suppression properties. It doesn't seem to. We've tried reducing volume on his hearing aids. We've tried reducing the gain on the mic input.

It's also my understanding, the problem is probably the sound from the hearing aid leaking through a bad seal in his ear, coming around and being picked up by the microphone in the hearing aid creating the squeal and then being picked up by the vocal mic. Am I assuming correct? Could there be another reason?

We've talked to a tech at Sweetwater and he had no advice. (Surprising)

Is there a gizmo that will fix this? Any advice and ideas will be much appreciated.

[Andy Vance]

Harold,
When the feedback occurs, is it always in the same frequency range or does it vary? The feedback never occurs if he isn't wearing his hearing aids?

[Dave Grafe]

Harold,
When the feedback occurs, is it always in the same frequency range or does it vary? The feedback never occurs if he isn't wearing his hearing aids?

Excellent questions these.

Hearing aids can feed back on their own if turned far enough up, and a mic MAY be able to pick that up slightly, but that is never going to produce feedback from the microphone on its own.

What cardioid mics DO pick up is the sound reflecting off of faces, hands, bodies and low ceilings from the mains and floor monitors, thus entering the mic from the front or side. The fabric a singer wears can even affect this, and If the monitor is not at 180° off-axis it gets even more complicated.

The "feedback reduction" in Shure's mics is simply their directionality, i.e. they don't pick up what is 180° behind them, and the assumption is that this is where the stage monitors will be located. If you refer to the plot below it is clear that the hyper-cardioid Beta 58A has several nasty hot spots in the high end as well as nodes off-axis that could increase the likelihood of feedback from reflections and/or monitors placed in one of these sensitivity nodes.

All this being said it is certain that the hearing aids have nothing to do with the problem anx that most likely the careful placement of monitors, a decent equalizer and a bit of applied science will put this issue to bed. Does anyone in your group know how to "ring out" a monitor sytem?

Hopefully this will provide some useful information on adjustments that you can make to settle this issue and give your singer a break from the guilt trip.

[Harold Bullard]

Great information. Thank you.

Andy - He has never tried taking his hearing aids out (yet) to see if it makes a difference, because he can't hear a thing without them. We have no way to measure frequency and we don't have an equalizer in the PA path. We have no problem with feedback ever except for him. No matter the venue, indoor or out. And only when he steps to sing. I have forgotten to ask if he can hear feedback any other time. And always very high pitched. My mom's hearing aids do the same thing. If she doesn't get a good seal, they squeal really high.

Dave - I don't know what "ring out" means. I doubt if any one else does either. We don't have an equalizer, though I've mentioned it many times we probably need one. We could probably adjust out the problem. He admitted his hearing aids are old and don't seal at all. He's going to get with an audiologist and have new molds made. And have the aids made out of rubber for a better seal. His old ones are hard plastic. And then we'll see where we are.

Thanks for your help.

[Walter Killam]

My Stepmother had problems with hearing aid feedback, it sounded like microphone feedback to me. You may want to look into in ear monitors if the hearing aids are picking up high volume ambient sound which causes feedback.

[Marshall Woodall]

I think your idea of having new molds fitted is the way to go. More than likely the feedback loop has nothing to do with the mic except for the fact that it is picking up his poorly isolated hearing aids. He probably has them cranked up and they are just in their own feedback loop. Unfortunately, this is what everyone hears when he steps up to the mic. good luck-

[Andy Vance]

Before I started getting new hearing aids made... those things are expensive, I would do a couple of tests to make sure it was the hearing aids. If he steps to anyone else's mic in the band, does it feed back? If someone else steps to his mic, does it feed back? If he removes his hearing aids and steps to the mic, does it feed back? What kind of PA are you using? What kind of monitors? Where are the monitors placed in relation to this singer?

[Ron Funk]

A group I played with had similar problem whenever the fiddle player tried to add vocals.

After trying various remedies, the source of the problem was found to be the fiddle player’s cellphone located in the front pocket of his bib overalls!

Issue resolved.