> the ringing in your ears is caused by distortion of the signal in the
> soundsystem. often sound systems are percieved as loud due to this,
> whereas a clean signal path will result in no ringing in your ears after
> the event.
Mmmmm - ringing is not just caused by distortion in the signal path -
it's also caused by bastard-loud PAs! Yes distortion makes it worse,
and probably brings it on at lower volume, but a clean and crisp and
pure PA system does not insulate you against tinnitus.
> when you leave a club and you have ringing in your ears and
> everything is muffled, this is called temporary threshold shift,
> and is your brain lowering the input level to make it more
> manageable for your ear
It actually does this by physically seperating parts of your inner ear,
if I remember rightly, it should always correct itself quite quickly
(within a few hours tops).
> but do thjis too often and it becomes permanent threshold shift....
> or as its more commonly know "deafness"
The process of permanent 'ringing' in the ears is slightly different.
That's caused by the little hairs in your ear that do the
vibrating/hearing. IIRC, there's a seperate hair pretty much tuned for
every frequency. When you get big impulse (or systematic abuse),
eventually you can end up with one of those hairs bent or broken. It
then is constantly spitting out erroneous nerve signals. Your brain
interprets that signal as that hair being constantly moved by the air
(when it's not), and you hear that frequency constantly.
There are two seperate things at work - the 'quietness' you hear coming
out of a club (that's a deliberate temporary defence mechanism), and
there's the 'ringing' you hear (that's the hairs under attack).
A hugely loud sound will give you permanent damage instantly - but a
lower level of constant noise will also erode your hearing permanently.
It's all cumulative. I listen to music relatively quietly around the
house, and when DJing if the monitoring is too loud or too nasty, I'll
stand with closed headphones on whenever I'm not mixing, just with the
volume down. HD-25s with nothing going through them are class for this.
I'll still stand in front of huge PA stacks and go clubbing with no
earplugs and all that, but I pick and choose my moments to be reckless.