Are noise-cancelling headphones making us deaf?

[jdimitri]

This just randomly popped into my head today

Noise cancelling=making 'antinoise' to cancel the outside noise. What if the noise outside is very very loud (eg planes)?
To cancel the noise wouldn't the noise cancelling thing have to do whatever they do at the same or higher level?
Or is one of those 'if you can't hear it it can't hurt you kind of thing'

Sorry if it's a stupid question

Btw.. http://en.wikipedia.org/wiki/Noise_c...ing_headphones has IEMs listed as noise cancelling.. what the

 

[HiWire]

I'm pretty sure the engineers thought of that right away - it was the first thing that came into my head when I read about active noise cancelling. The anti-noise circuitry probably has a maximum, beyond which it will either quit entirely or stop amplifying the anti-noise. It's one of the things that prevents me from getting this type of can, though. I'm not a big fan of adding noise of any kind to the signal chain - I don't like the hiss that it adds either.

 

[GlorytheWiz825]

From my understanding, all the "anti-noise" is done inside the circuit and doesn't get passed to the ears to cause damage. Otherwise, to noise-cancellation technology would render us deaf. Besides, noise-cancellation headphones don't work nearly as well as IEMs. Just get a pair of decent IEMs for isolation and problem solved. No need for bulky headphones which require batteries to operate effectively.

 

[nikongod]

the "anti noise" actually combines with the real noise, and they "neutralize" each other.

 

[milkpowder]

Quote:

Originally Posted by nikongod /img/forum/go_quote.gif the "anti noise" actually combines with the real noise, and they "neutralize" each other.

basic wave superposition that I learned from Physics A level...

Hence, the amplitude is 0 and you don't hear anything. However, they don't always get it right, so sometimes you do hear a faint hiss.

That's probably an extremely watered-down explanation of what actually happens.

 

[jdimitri]

Ah that made everything clearer..
I thought the music AND antinoise would be coming out of the drivers into your ears and you know, making a noise orgy



..but appearantly not

 

[angler31337]

Quote:

Originally Posted by jdimitri /img/forum/go_quote.gif Ah that made everything clearer.. I thought the music AND antinoise would be coming out of the drivers into your ears and you know, making a noise orgy ..but appearantly not

Even if it were the case, as long as the "anti-noise" is in the correct phase you should get amplitude reduction.

-Angler

 

[warpdriver]

Quote:

Originally Posted by angler31337 /img/forum/go_quote.gif Even if it were the case, as long as the "anti-noise" is in the correct phase you should get amplitude reduction.

That is correct, it doesn't matter where the antinoise is combined, the total effect is that the level of sound *at your eardrum* is overall lower.

The anti-noise is usually only effective up to about 15dB total noise reduction under 1000Hz, which isn't a heck of a lot. Most IEM's can do better than that.

 

[eVITAERC]

Furthermore, if you're wondering where the original sound wave energy went, the physics of wave generation dictates that whatever produced the anti-wave must also absorb the energy of the wave it cancels. IE, the outside noise is "absorbed" by the speaker drivers, in terms of energy accounting.