Do noise cancelling headsets protect or damage your ears ?

[digits_]

Hi all,

I was wondering if there are any studies/reports regarding the effect that noise cancelling headsets have on your ears. I am not talking about the comfort level -most of them do indeed lower the level of sound you hear-, but the effect on the health of your ears with prolonged use.

I know the theory behind them, and it sounds great, but in practice you can't ignore the fact that:
* you have an extra speaker close to your ear that generates basically the same level of sound. This energy has to go somewhere, right ?
* apparently you can have all kinds of lower level interference effect, which you can't hear but are still causing pressure to your ear drums

Looking for some other point of views.

Greetings,
Digits

[Pop n Fresh]

The energy is theoretically in opposition of the waves that enter the chamber thus canceling out the noise.

I know what you are thinking though and agree that it seems possible the pressure could be additive.

[Nark]

High school physic teacher might be able to better explain,
However noise canceling works, that if two wave lengths of equal magnitude (sound) are generated 180* from each other at equal distance, each will cancel the other out, and no sound is heard.
A very basic way of describing ACtive Noise Cancelling.

I started using ANC's in 2008, and having accumulating several thousand hours since then, my base line audiology hasn't changed. (Comparing 2009 and 2014 audiology reports). This is me, not the whole.
I use custom molded CEP's in the military, and DC X-11's in the Ejet and Stinson.

[Taiser]

Guys wear them hear at firearms training all the time and they have ZERO issues with hearing, even after years of use. Pop N Fresh is right, they cancel the noise with an inverse sound-wave so it's not like you have a second source of sound blasting in your ear.

[CpnCrunch]

According to this article, ANR headsets do protect your hearing from damage because it is the low frequencies that cause hearing damage and ANR headsets are very effective at removing those low frequencies:

http://www.avweb.com/news/avionics/1832 ... directed=1

The wavelength of 100Hz is 11 feet, so you're not going to get an interference pattern inside your ear - it will basically be entirely cancelled out.

[Heliian]

Hearing damage is cumulative, and you are correct that your hearing is still getting damaged, but at a much lower rate. I haven't seen any studies but I would wager that you are much better off with the anc's regardless.

[Forestdump]

Just my 2 cents. Damage to the inner ear can occur due to transmission of energy through the skeletal structure. Example: Ear plugs at a rock concert will do nothing to protect you from energy transmitted to your inner ear via your cheek bones and skull. If you are serious about protecting your hearing wear a helmet. Believe it or else.

[Chuck Finley]

Is it better if the said helmet is made of tin foil?

[Forestdump]

Probably not.

[pez]

Is it better if the said helmet is made of tin foil?

Always.

[ogc]

I wear a noise cancelling set and ear plugs undernieth. I fly in a loud plane, some people think its overkill but ever since I started doing it ive been noticebly less fatigued and longer legs sre much easier to fly. I also picked a headset that had good passove protection as well as ANR, I dont trust that voo doo completely.

[ahramin]

To answer your question digits, ANC doesn't "mask" or "hide" sound from your ears, it cancels it. Reduced sound means reduced hearing damage.

If you're in a loud plane, check out Telex's 50D. Worth every penny.

[Colonel Sanders]

No one cares, but years ago, when ANR
headsets first came out, there were instances
of hearing damage when the noise cancelling
logic malfunctioned and got very, very loud.

I'm probably not allowed to mention differential
equations in this crowd, or "poles in the right
hand plane" for those that like to model everything
(like an RLC cct) as a 2nd order O.D.E.

I keep telling people - and they don't give a
sh1t - that divergent oscillations are very, very
bad. See "flutter". See every wrecked taildragger.
See an unstablized ILS. Google PIO. Watch any
student pilot in the flare as he porpoises down
the runway, in a furious attempt to remove the
nosewheel:

http://www.youtube.com/watch?v=NMmHYWjEmkY


Keep those learning experiences coming!

[BTD]

No one cares...

I'm probably not allowed to mention...

I keep telling people - and they don't give a
sh1t....

!

Maybe nobody listens because you are always telling people how worthless they are and how wonderful you are.

This WAS a pretty respectful thread.

[Pop n Fresh]

Easy BTD I think he was saying in his own way, "While highly unlikely there is a slim chance ANR headset technology could malfunction and harm your hearing."

http://www.youtube.com/watch?v=NMmHYWjEmkY

Did noise canceling head sets cause that?

Be careful digits!

Are you in Sask, Manitoba or what?

I'm probably not allowed to mention cooking in this crowd but... You never came by YYC so I could make you dinner and ask questions about the North Pole! I has a second job where they pay me now, I could buy fancy wine ( not too fancy ) to go with tenderloin. I made chicken with baked potatoes yesterday that was excellent.

[5x5]

I has a second job where they pay me now,

Is it as an apologist?

[looproll]

I've been using a Telex 50D since shortly after they came out. My audiograms are consistently stellar.

[Pop n Fresh]

I has a second job where they pay me now,

Is it as an apologist?

No. I think mediator did come up on an aptitude test once.

[digits_]

To answer your question digits, ANC doesn't "mask" or "hide" sound from your ears, it cancels it. Reduced sound means reduced hearing damage.

If you're in a loud plane, check out Telex's 50D. Worth every penny.

Yes, and theoretically that works perfectly. In practice, it works for a certain frequency range, and only partially (otherwise you would hear absolutely nothing). My concern is: what happens outside of that frequency range ? Sounds/waves that we just can't hear, might still be damaging to your eardrums. Or not. I am looking for some (dis)proof for that.

But definately some good points in posts above. Keep it coming !

[Pop n Fresh]

As for pressure, if it is a slow build up it should go in or out of the tube going to your sinus cavity and in or out your nose. That protects the ear drum from pressure change. Yes?

The article linked in the "I'm a flautist and wonder how loud cockpits are?" Thread says low frequencies are worst for damage but it always seemed like high frequencies ( crashing cymbals) hurt more often.

[ahramin]

If I have your original question correct you think the speaker in the headset that produces the NC signal *apparently could put pressure on your ears at a frequency you can't hear and could do damage? Can you post a link or more information on this *apparently part? I've never heard of this but if you have a source I'd be happy to have a look at it and try and figure out what they are talking about. Can't say it makes much sense so far. Pressure doesn't have a frequency, I'm guessing you mean an inaudible sound frequency, not an air pressure.

Keep in mind that anything under 75 decibels will not cause hearing damage no matter how long you are exposed to it, and you are unlikely to fail to notice a sound above that being produced right next to your ear at any frequency. Even if you couldn't hear it you'd still feel it.

[digits_]

Hmm, I might have misunderstood that.

It's not a very trustworthy source, but on this link nr 10: http://www.ebay.com/gds/10-Pros-and-Con ... 920/g.html

The fact that you feel pressure when using them, means that the ANC isn't perfect and is generating something you wouldn't expect. I have been looking for a more reliable source, but couldn't find any. Hence the questions here.

[CpnCrunch]

The fact that you feel pressure when using them, means that the ANC isn't perfect and is generating something you wouldn't expect. I have been looking for a more reliable source, but couldn't find any. Hence the questions here.

Here is an explanation from Bose:

http://www.nytimes.com/2009/12/03/techn ... d=all&_r=0

“The sensation of needing to ‘pop’ your ears is normally caused by a static air-pressure difference across your eardrums — something that occurs in an ascending (or descending) airplane. Headphones that reduce more low-frequency sound pressure from surrounding noise (like the QC15 or our Aviation headset) is perceptually similar to the ‘thin’ sound caused by a static air pressure difference. We believe this can explain the sensation of pressure on the ear when none is actually there.”

So the 'feeling of pressure' is apparently just an illusion.

[ahramin]

Never having felt this pressure I'm not sure what it is and can't really comment about it other than to say that your ears feel a far greater pressure every time you go down an elevator so I wouldn't worry about it.

This discussion is starting to remind me of people who are not getting vaccines because of the health risks so lets look at a few facts:

1. Airplane cockpits are noisy, most are noisy enough to cause hearing damage.

2. Many of these cockpits have noise so loud and at such a frequency that wearing a regular passive headset is not sufficient to prevent hearing damage.

3. In all but the most frightfully noisy airplanes a good ANC headset fitted and working properly will reduce the noise at the worst damaging frequencing down to a decibel level that is no longer doing any hearing damage.

It would not make sense to me to take on all the hearing damage which has been shown to happen using no or passive headset only, in order to prevent whatever damage would happen from inaudible signals I can't sense. Particularly since we cannot find any literature that these inaudible signals at super high decibel levels exist.

[white_knuckle_flyer]

Never having felt this pressure I'm not sure what it is and can't really comment about it other than to say that your ears feel a far greater pressure every time you go down an elevator so I wouldn't worry about it.

This discussion is starting to remind me of people who are not getting vaccines because of the health risks so lets look at a few facts:

1. Airplane cockpits are noisy, most are noisy enough to cause hearing damage.

2. Many of these cockpits have noise so loud and at such a frequency that wearing a regular passive headset is not sufficient to prevent hearing damage.

3. In all but the most frightfully noisy airplanes a good ANC headset fitted and working properly will reduce the noise at the worst damaging frequencing down to a decibel level that is no longer doing any hearing damage.

It would not make sense to me to take on all the hearing damage which has been shown to happen using no or passive headset only, in order to prevent whatever damage would happen from inaudible signals I can't sense. Particularly since we cannot find any literature that these inaudible signals at super high decibel levels exist.

A very sensible post.

You may as well start worrying about asteroid collisions as worry about hearing damage from sound frequencies that you cannot detect. The possibility of such damage either exists ( I do not believe it does ) or it does not. If it does, then we are all screwed anyway...pilots and non-pilots alike. Think about the wavelengths of sound bouncing around you at any moment that you do not perceive.