unusual hearing issue -- what is this?

several decades ago, Prof. Don Campbell showed me that I have an unusual hearing condition as follows -- tap a tuning fork and listen to the tone. Then touch the base of the still vibrating tuning fork to the mastoid bone -- for me the tone changes significantly when this is done. Don commented that this rare condition is why I always sing off key -- what I hear from outside via my ears is NOT the tones I [try to] reproduce with my voice -- my hearing issue automatically corrects my singing to be off key. I've tried online but can not find a description of this condition -- what is this? [I don't think there is any treatment other than not singing.] {I can hear just fine -- but, apparently the tones are all "wrong".}

thanks for any lead or link on this.

Spock (rhp)2016-10-17T10:59:15Z

Rinne test. Yes. sounds like it, except -- I have bilateral excellent hearing. In my case, it is the tone of the tuning fork that seems different when the sound is conducted in the air. The six or so references I read do not address this. Thx to TSM_908 for naming the test. Anyone else care to comment?

Anonymous2016-10-17T07:57:25Z

This I think sounds like the Rinne test - see https://www.youtube.com/watch?v=J5o2gUHDfY4

paty2016-12-14T02:08:19Z

Your too told ***** **** happens