how long is the essay, all these sites have good information on them.
http://history.sandiego.edu/GEN/recording/notes.html
http://www.videointerchange.com/audio_history.htm
http://www.recording-history.org/HTML/tech.php
http://www.rupertneve.com/company/history/
http://www.solid-state-logic.com/company/history.html
http://www.historicalvoices.org/oral.../rec-tech.html
http://books.google.com.au/books?q=audio+recording+history+books&ots=BLHpalSC Ei&sa=X&oi=print&ct=title&cad=legacy
Alexander Graham Bell experimented with a Phonautograph in 1874, shortly before Edison's invention. Attempting to discover how the ear detected sound, he used a human ear (including the internal parts) from a cadaver, attaching a stylus to the eardrum and using it to make a recording.
Bell's ear Phonautograph was a very unusual variation on the basic technology. The recording mechanism was the human ear. By removing a chunk of skull including the inner ear from a human cadaver, and attaching a stylus to the moving parts of the ear, he was able to use this bio-mechanical device to make a recording of the sounds that entered a recording horn. It recorded on a moving glass strip, coated with a film of carbon, so there are probably no original recordings from it. When he learned of the invention of the phonograph, Bell wondered why he didn't think of it himself.