The nuraphone plays a range of tones into the ear, and then measures a very faint sound that your ear generates in response to these tones called the Otoacoustic Emission (OAE). This tiny signal originates in the cochlea and vibrates the ear drum, turning it into a speaker and playing sound back out of your ear. Yes our ears make sound! This sound is about 10,000 times smaller than the sound that went in.