[thedoc (OP)]

Nithin Ramadurai  asked the Naked Scientists:
   Hi Naked Scientists,
I have a question for you guys: is listening to white noise helpful or harmful for the ear drums?
I've come across numerous articles purporting the benefits of white noise to make babies sleep or to keep one productive in the office by claiming to  mask background noise. Most of these articles are anecdotal and/or based on small studies without references to the actual studies (which I'm not wholly convinced by).
I tried it for myself (using headphones) and found it completely useless in drowning out background noise unless I raised it to a high volume, at which point, it was annoying to listen to. It also temporarily made my ears ring with the sound associated with tinnitus for a good 30 seconds (at a low level) after ceasing the white noise.
Also, is the hypothesis of using white noise based on destructive interference of outside sounds?
Let me know. Thanks.


Regards,
Nithin(from Wakefield/Boston, MA, USA)

 
What do you think?

[Colin2B]

Hi Nithin
It is the level of the sound that does the damage rather than any particular spectrum, so it is best to keep the volume of any sound down as low as possible.
Most of the studies of masking for tinnitus are based on very low levels which are just audible. The brain is aware of these sounds and after a while starts to ignore them, along with the tinnitus which tends to have a spectrum similar to white noise. Some studies have shown that limiting the bandwith of the masking signal so it is centred on the tinnitus frequencies can help.
The problem with all the research is that it is very subjective and it can be difficult to remove any placebo effect. Also anything which directs the mind towards tinnitus tends to make it more noticable.
No, the hypothesis is not destructive interference of outside sounds, because tinnitus is internally generated by nerve endings of the fine cillia in the inner ear.

[evan_au]

is the hypothesis of using white noise based on destructive interference of outside sounds?

No. White noise is based on auditory masking, where your ears and brain pay attention to the loudest sound in a frequency band, and ignore lower-amplitude signals. This effect is used in MP3 sound recording to compress audio signals that can't be heard.

You are thinking of noise-canceling headphones, which are based on destructive interference with outside sounds, using "anti-noise". These headphones are expensive, but they will not cause ringing in your ears because they reduce the outside sound levels.
A cheaper (and probably more effective) alternative is to go to your local building supplies store, and buy a bulk pack of earplugs, as used by tradesmen using power tools.

I raised it to a high volume.... It also temporarily made my ears ring

This is definitely too high volume! This will harm your ears if you use it for a long time.
White noise is really only useful for disguising low levels of ambient noise (like a quiet office), using white noise which is low enough to be unnoticeable; sound peaks in the environment will still be quite audible, like people talking to you.
White noise is not helpful if you are already in a very noisy environment; use one of the methods above that reduce the noise level, instead of adding to it.