Hearing aids: high pitched squeal upon hugging. What's the deal?
December 25, 2011 7:21 AM   Subscribe

Hearing aids: Why do they emit a high pitched bzzzzzzz when you hug someone who is wearing one, and does the wearer hear it, too?
posted by Stewriffic to Grab Bag (13 answers total)
If it happens when your head is next to their head, you're probably setting up a sound reflection that's causing feedback. It's also totally possible that it's happening all the time and you're just not close enough to hear it, which probably answers your second question. I've witnessed this many, many times at concerts, where someone is emitting a squeal (noticeable when the audience quiets down) but has to be tapped on the shoulder and told about it.
posted by range at 7:29 AM on December 25, 2011 [1 favorite]

Seconding that it's probably buzzing all the time but you only notice it when you're close to them.

Be thankful for improved modern technology. 20- and 30-odd years ago, my paternal grandfather wore hearing aids that went "squeeeeee" most of the time, and "SQUEEEEEEE" when tweaked a little differently. To answer your second question: no, the wearer does not hear it.

Grampa: "WHAT??"
Us: *motion to ears while grimacing*
Us: *nodding vigorously*
Grampa: "GODDAMMIT, GODDAMNED HEARING AIDS" *fiddles with hearing aid till we motion that it's better*
posted by fraula at 7:36 AM on December 25, 2011 [3 favorites]

Feedback. And no, they don't hear it as far as I know. My ex-boss wore one that routinely interacted poorly with the cell phone and he never seemed to notice. (Much to my chagrin.)
posted by sm1tten at 7:43 AM on December 25, 2011

I wear two. Expensive Oticons. Recently got them. It's feedback, created when something moves close to the aid, like a hand or another head. Or if I turn my head and my ear comes close to a car's headrest, or a couch cushion--it squeals. It doesn't squeal all the time, only then. Yes, I hear it. Damned annoying. But now I hear better. Well, a little better.
posted by fivesavagepalms at 8:02 AM on December 25, 2011 [2 favorites]

They probably hear it. I have aids that are about 12 years old. . .some of the first digital ones, and, while my brain can tune out the feedback, others with acute hearing can hear it and call my attention to it. It is probably caused by an imperfect seal somewhere along the path of sound, probably an ill-fitting earmold, due to wax buildup or improper insertion.

When someone calls my attention to it, I tend to get very, irrationally, chagrined, once to the point of walking out of a meeting when someone mentioned it. Not annoyance at THEM, but just a deep embarrassment that I had tuned this noise out, rather than fixing it.

Emotionally, hearing aids are not like glasses, due to the interactions a hearing-impaired person has had, throughout his or her life. There is a charge to it.

But to get back to your question, your head, and the small electrical field around it may well be interacting with that person's aid. I know that during yoga class my tends to feed back if my head (ears) are too near the mat, during certain postures.
posted by Danf at 8:07 AM on December 25, 2011 [2 favorites]

Whether or not they can hear it is probably dependant on the type of hearing issues they have and just how high pitched the squeal is. High frequency hearing goes down hill fast as you get older.
posted by Kid Charlemagne at 8:25 AM on December 25, 2011

I just got hearing aids and I hear it. I sometimes feel a little bit awkward when people go to hug me because I'm worried they will squeal.
posted by katinka-katinka at 8:27 AM on December 25, 2011

I recently started wearing expensive digital hearing aids, after an unsuccessful attempt with older analog aids 15 years ago. The difference can't be overstated. If Grandpa can't hear his aids squealing, get him back to a good specialist and get him decent hearing aids. They're expensive(thousands,not hundreds), not covered by most insurance (yeah, thanks, that's really fair) and manage sound much better. There are new options for mobile phone integration. When I got a new mobile phone from work, I insisted on the one that had the best audio and best hearing aid options(Thanks, Motorola) for me.

Hearing aids aren't like glasses; they take more time to adjust to, because the brain has been doing a lot of processing to try to understand sound. I've had mine 6 months now, and am finally at the point where I miss them if I don't wear them. They are strongly associated with age, and I always feel like wearing a badge that says "Genetic hearing deficit, not age-related, and No I didn't listen to too much rock & roll."

I disclosed my hearing impairment at work. I asked people to speak up, to look at me when they speak, not to speak with their hand in front of their mouth. Zero cooperation. Now, with aids, in meetings, I can usually hear @ 75% of what The Mumbler says, in his soft voice, with his hand in front of his mouth, and 90% of the rest, even with multiple talkers. When I go to the store, I often can't hear the cashier, and it's amazing how many people do not respond to a cheerful, polite "I have poor hearing, could you please speak up" or, worse, look down and keep mumbling softly.

If someone you know has a hearing impairment, get them good hearing aids, properly tuned, and a phone that works well with aids. Look at them when you talk to them, speak up a little, and be patient. They aren't stupid, or mishearing on purpose. They may not wear their aids because they have crappy aids; maybe you can help with that. If the aid squeals a little, and there's nobody else around, say "Does that feedback bother you? Is there anything I can do?" Many people may prefer not to discuss it publicly, but in private it should be okay.
posted by theora55 at 8:59 AM on December 25, 2011

When my mother loses one of her hearing aids, she walks around with the other one held out, moving it around, to find the other one using feedback.
posted by dhartung at 9:26 AM on December 25, 2011 [3 favorites]

Hearing aids squeal for the same reason that you hear the speakers squeal in an auditorium when the amplifiers are set too high.

All hearing aids have a microphone, an amplifier and a speaker. Since the microphone and the speaker are so close to each other, some of the sound from the speaker leaks out of the ear and gets picked up by the microphone which amplifies the sound some more which makes the speaker louder which leaks even more into the microphone, etc. This is called positive feedback and quickly the speaker ramps up to its maximum output which causes the squeal.

Usually the bit of sound leaking out from around the speaker just dissipates before it can be picked up by the microphone, but if you place your hand, head or some other object next to the ear, the leaking sound gets reflected back into the microphone to cause feedback and the squeal.

If you can hear the squeal outside the ear, you can imagine how loud it is to the wearer. However, some wearers have lost all ability to hear at high frequencies, even with a hearing aid, so won't notice the squeal.

Many modern hearing aids have feedback reduction, but it can't be eliminated entirely. Feedback is more likely the smaller the hearing aid, because the microphone and speaker are closer together, the higher the amplification the wearer requires which leads to more leakage, and poor the fit of the hearing aid. Most hearing aids for people who require high amplification are designed to fit securely in the ear to seal the sound from the speaker inside the ear from the microphone on the outside of the hearing aid. A poorly fitting hearing aid can be more susceptible to feedback because of feedback leakage.
posted by JackFlash at 10:16 AM on December 25, 2011 [2 favorites]

My wife and I call this the "hug robot". Because when we hug it sounds like a robot.

To answer your second question: no, the wearer does not hear it.

Or, yes, they absolutely do. It depends on what type of hearing loss they have. (It is extraordinarily loud for me because it is HAPPENING IN MY EAR VERY LOUDLY -- I can hear high pitches just fine; my loss is mostly in the middle pitch range, where human speech is. Lucky me.)

It may also depend to some extent on the type of hearing aid.
posted by ook at 10:18 AM on December 25, 2011

Sensitivity to feedback depends on the hearing loss and the hearing aid. I have profound high-frequency hearing loss and wear hearing aids in both ears. With my last set of hearing aids I could hear the feedback quite well, as the feedback had a low enough pitch to be in my hearing range. With my current set, I can't hear the feedback because it is a higher pitch and out of my range. This is very annoying, because I therefore don't know when it's happening, and can't respond by moving my head to make it stop, or explain it to perplexed people around me.
posted by amusebuche at 2:58 PM on December 25, 2011

Thanks everyone!
posted by Stewriffic at 4:50 AM on December 26, 2011

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