Richard Crowley wrote:

A friend of me complains her mobile mobile phone's mic doesn't work well
since she have been to night club a few weeks ago.

Didn't get some kind of alcoholic beverege dripped into it, perhaps? :-)

If not that, at least very high humidity from being surrounded by sweaty
bodies? Electrets aren't best suited to humidity.

As for sound level, I'd have thought 95dB could easily be exceeded by
shouting in to the phone, and most mics don't suffer distortion (never
mind permanent damage) until much higher levels than that.

Anahata