I had brought this up once many years ago on another forum, but I got skewered and fried for it.

Otoacoustic emission - http://en.wikipedia.org/wiki/Otoacoustic_emission

These are REAL sounds generated within the inner ear. There are two types, spontaneous and evoked. In either case they can be detected with an instrument.

Evoked otoacoustic emissions (EOAE) are caused by some external source. They are used clinically to test infants for hearing problems. Since a baby can't tell you if they hear a tone or not, an OAE is evoked by a special instrument and then measured. If an OAE cannot be evoked, the child is likely deaf in that ear and appropriate treatment measures can be taken.

Spontaneous OAE's (SOAE)are a less understood. It is thought that to be related to the cochlear amplification process.

Personally, I hear these sounds all the time. Many times I can even identify the source that caused it. I had a finch that would sing certain tones that would cause my left ear to just "wig out". Not so much a tone as it felt as if it was literally wiggling inside, a very uncomfortable feeling. In other cases it was caused by a loud sharp sound. An obvious example is the ringing in your ears after a firecracker goes off too close. I've even had them happen with pressure changes - when I yawn and the pressure 'pops' my ears.

I also may have slight tinnitus, likely caused by years of riding a motorcycle. Although I wear a helmet (open face), the wind noise is still quite loud at 70+ mph. I started wearing earplugs over ten years ago when I first noticed the problem. I had started to notice my ears would ring loudly after my rides. Since wearing earplugs it has not gotten any worse. It's very slight and not bothersome.

Brian

• Otoacoustic emission