Hearing Damage

[lcaillo]

I saw mention of the threshold for hearing damage in another thread and remembered seeing this. It is good visual reference for anyone concerned with hearing damage. Most of us are probably fine, but I have a couple of clients that should look hard at it. The big concern these days is the level on headphones.

http://www.cdc.gov/niosh/topics/nois...okatnoise.html

[hyghwayman]

Thanks for the link LC

[DougMac]

Thanks for bringing this up. I'm amazed when I read folks bragging about being able to get 100, 105 or even 120 db out of their system, especially their subwoofers.

I cranked my current system up to what I thought was loud, the very loudest I was likely to play it. It averaged around 80-82 db, with occasional peaks hitting 88db. This was much louder than I normally play it.

I also wear hearing protection when working with power tools. Sometimes it's a PITA, but Father Time is diminishing my hearing enough as it is without me helping!

Doug

[avaserfi]

DougMac wrote:

Thanks for bringing this up. I'm amazed when I read folks bragging about being able to get 100, 105 or even 120 db out of their system, especially their subwoofers.

There are differences between frequencies and how they effect hearing. For example: one can be in a room with a subwoofer playing a 30Hz tone at 120dB without any hearing loss due to their size, but put the same person in a room with a 500Hz signal at that level for an extended period of time and it will be very painful...This is why it is perfectly safe for one to have their subwoofer capable of 100+dB with no danger.

Just remember, this is a good, but simplified version of the situation.

[lcaillo]

Remember that with music and movie content, you don't have continuous levels all the time. The durations that they give are for noise at constant levels on a daily basis.

[superchad]

I think its easy to get peaks over 100db but general audio level within those peaks is much less, but I do listen around 90-95db for extended periods. One may consider if their system is too much at higher volumes it can not only be their comfort level but also lack of amp power, lower performance speakers and associated gear or poorly placed speakers and bad accoustics.
I have had systems that couldnt crank because they didnt sound good....but a well performing system in a good room will surprise many as to how loud one can listen and still be pleased with its sound. A prime example, my dad went from Legacy speakers and Lexicon pre to Vandersteen speakers and Audio Research tube pre, his listening increased 10db instantly as it still sounded fantastic at higher levels, all along it wasnt the volume that was the problem,,,,,,,,,,,,,,it was the system.

[jakewash]

As soon as you go above the rated db levels for your speakers the amp requirement go up significantly per channel in order to handle the momentary spikes cleanly. There area number calculators on the web that will show you the extent of this increase.

Listening at 80 db on speakers with a sensitivity of 91db, listening at 8ft away and music with a dynamic range of 10db, it now takes about 5W per channel to cover the dynamic range, increase that 80db at the listening position to 95 and it now takes about 150W to cover the range.

This makes it easy to see why it is hard to drive speakers to very loud levels cleanly.