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Discussion Starter · #1 ·
I have a 2012 Volt and have always been bothered by some of the extremely high pitched noises it makes, in particular for my car it's when decelerating in charge-sustatining or mountain mode. Discussion of these sounds can be found here: http://gm-volt.com/forum/showthread...nnoying-high-pitched-sound-any-way-to-stop-it

Note: this is not a discussion of the "buzz saw" like sound that indicates a failing bearing. Rather, I'm asking about the normal electronic sounds, which seem to be in the 10-20KHz range - many folks can't hear it at all, but if you can, it can be highly annoying and headache-promoting.

Is there anyone on the forum who can hear these sounds, and can comment on whether there are any model-year differences?
 

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I have a high pitched whine like you mention. Coming from the rear off of the APM (power inverter) that charges the 12V battery. I went in for a tire rotation on Monday and they did a "recall" which was a reprogramming of the APM. Seems a little quieter. Until now, it was considered SOP. Even my Volt Advisor said it was normal and not to add any sound deadening around the APM or it would overheat. Younger people can hear it more than older. It is right about 13,000 Hz. My daughter doesn't like it and says it js one thing she doesn't like about riding in the Volt.

Some would equate the noise to tinnitus.
 

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I notice this noise in my 2013. Not all the time, thankfully, but only in certain modes, I think decelerating is one case.

It is audible to me, but it is below the level where it would be annoying. If I was 30 years younger (I'm 57) it would definitely be very annoying, but this is one case where age-related high frequency hearing loss might be beneficial.

It would be funny if only older people bought the Volt because all the younger ones couldn't stand to be in the car because of the noise.

I suspect this may be a high frequency transformer mechanically vibrating at 13kHz or whatever the frequency is. Something has to be mechanically moving to generate the sound - you can't hear a radiated electromagnetic field.

It would be nice if GM could come up with a software fix for this, like changing the switching frequency, but I suspect it's a finely engineered system where changing the frequency wouldn't be so easy. If it required a replacement of hardware, I don't the cost vs benefit would justify it.

Like the previous poster, if it bothers me, I just turn on the radio and I don't notice it with the music playing.
 

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My '14 makes high pitched noises too - some are more or less audible inside vs outside.
The ones I notice in particular are a high pitched noise when the car is on (most audible outside), and a varying pitch that goes with the car's acceleration (not sure how audible it is outside, but I can hear it inside).
 

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My 2014 makes all kinds of noises but coming from a Toyota Prius I'm already familiar with these so I'm not really bothered or concerned. I actually like the one I hear when taking off from a full stop. It sorta sounds like the flying cars from The Jetsons. The one I don't really care for is the really high frequency one I only hear (thankfully) when I'm parked with the system on and I get out in front of the vehicle to retrieve the mail.
 

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Only hear it when in CS mode during heavy regen or accelerating... doesn't appear when gently doing both.

If the APM is indeed the source, it might be possible to put some padding in there to muffle it some.
To me however, its almost as if it comes through the sound system speakers....

The wife does not hear it, but I do. I estimate it to be between 15000-16000hz.
To give some perspective, its slightly lower than an old CRT TV set's flyback frequency. (remember these?)

Would not put it past me that old TV sets were a leading cause of tinnitus in many children. lol
 

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It is more noticeable with the windows down.
I can hear it during very slow speed operations.
I sometimes wonder why tinnitus is coming on while driving after a while.

Why can't a sound blocking shroud cover the APM ( if this is where all this sound is coming from )?
It and the battery charger share a dedicated liquid cooling system.

Man, this thread makes me go back to wearing ear plugs while on long drives. You gots to save them drums...
 

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I have a 2013 Volt and I experience the same issue with the high pitched noise. The noise is similar to what you might hear if you put your ear to a traditional incandescent light bulb in lamps. I'm at a point where I can always hear it when the car is emitting that noise but it's hard to point it out to others. I've also read posts where it states that that level high pitched noise is not audible to everyone. Some people are able to pick it up, while others may not. I've taken it to the dealer multiple times and each time they're giving me answers like 'it's normal' or 'it's working as designed'. The noise occurs during acceleration, around 30 mph speed, and when braking. It's more prominent in Extended Range mode. If this is working as designed, then the design is flawed, because nothing should be designed to give headaches to the driver.
 

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I can't hear anything over the sound of my passengers screaming.
 

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Discussion Starter · #17 ·
Our lease is nearly up, so the other day my wife and I test-drove a 2014 and 2015 Volt. Strangely, we both felt that the 2014 was quieter than the 2015, both in engine noise and in high pitch electronic noises. The 2015 only had 9 miles on the ODO but the 2014 had 150, so maybe there is some breaking-in time that could explain the difference? It was weird.
 

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The one car that makes my tinnitus work to my advantage. Some friends riding in the car have asked what the high pitched noise is. Ive not noticed it much.
 
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