I already know that earwax helps by keeping out bacteria, but is it any way a defense against sound. for example if I wear earphones all day will extra earwax build up to defend my eardrum?
What?
Probably not, but earwax does evaporate and if you wear ear muffs all day they would slow down the process and make it seem like there is more earwax.
Excess earwax would have a marginal effect on protecting your hearing from prolonged exposure to loud sound. In most cases, excess earwax doesn’t have any effect on hearing at all, since all sound usually needs is just a little bit of a gap between the earwax and the ear canal wall in order to make it through unimpeded to the eardrum. In the cases where I did see an effect in a patient, it was usually in the form of a mild 10 to 15 dB shift in hearing, and that was only if the ear canal was completely occluded by earwax.
Bottom line: I wouldn’t rely on earwax to protect your hearing, and it would do virtually nothing to protect your eardrum.
Earwax doesn’t evaporate. Normally, earwax (also known as cerumen) flakes off and migrates out of the ear canal on its own. Some people are prone to cerumen build-up for various reasons, and one of the more common reasons is that they use hearing aids. This is the reason why hearing aid users are extremely prone to excess cerumen in the canal, which can cause problems both for the hearing aid function and for the potential benefit the person may receive from the hearing aids.
Not to rain on your parade doc but anything water or oil based is subject to evaporation.( has a vapor pressure) Although the residue of the ear wax may flake off this only happens after it has been dehydrated (has evaporated) I would imagine that this evaporation would reduce the volume of the wax, therefore if the evaporation didn’t happen there would appear to be “more” earwax.