Kate Taylor asked:
Dear Naked Scientists,
I'm in the U.S. and I LOVE LOVE your podcast. I listen to it while I work -- I'm a graphic designer, so when your program is on I've got sort of a left-brain/right-brain thing going on.
Anyway, I was wondering why we have earwax. What's it for and how is it made? What would happen if we didn't clean it out every once in awhile, besides possibly get very annoying?
Keep doing awesome science and bringing it to the public in interesting ways!
Cheers from California!
Kate in sunny Santa Clara
Earwax is made in the outer canal of your ear. Your outer ear is basically the bit that you can see. Itís the bit that funnels all of the pressure Ė the sound wave pressure - and funnel it into your middle ear and your inner ear which then converts those sound wave pressures into electrical energy which you can then use to hear. Earwax ,or cerumen, basically acts as a lubricant to help the sound waves to travel through, and it also protects against nasty bugs sitting in your ear and multiplying there and causing infections. So, perhaps counter intuitively, itís actually quite a cleansing thing to have as long as you don't have too much of it. If there's too much of it then it can cause a blockage and prevent the sound waves from passing through into your middle ear and therefore cause impairments or problems with your hearing.
Ceruminous glands are a special skin gland found in the outer ear canal that secrete directly onto the skin or into hair follicles. Their secretory product combines with sebum of adjacent sebaceous glands to form cerumen, or ear wax. It is often suggested in text books that ear wax protects the very thin skin in the external auditory meatus, but it is not clear why a much smaller amount of cerumen would not be adequate. Recent studies have found that cerumen repels insects, and it contains lysozyme which breaks down bacterial cell walls.