What would you do with epoxy putty laying around?
The process is simple – mix up some epoxy putty, jam it in your ear, let it mostly harden, take it out, drill holes for sound, and mount normal earbud speakers to them. Et voila!
This article may have one of the best disclaimers ever:
WARNING – This tutorial advocates jamming things in your ear which are not made for earal consumption. Some people are allergic to epoxy (or develop an allergy after working with it) and may experience an allergic reaction that could conceivably involve a swelling of the ear canal and/or complete anaphylactic shock, maybe even death (hey, it could happen). You may also have a specific hooked form of ear that prevents you from removing the epoxy once it hardens. You might also, perhaps, have some sort of seizure epilepsy that makes you throw up uncontrollably when you stick things in your ear. Please consult your otologist before attempting this procedure. I take no liability for emergency room bills, ICU bills, coma support, or any other expenses incurred from actions resulting from the reading of this article. – Link