Dipla...What?

When I purchased a new pair of hearing aids, my audiologist explained that they have a “boot-up” sound, to let me know I turned them on successfully.  It’s a five-note, upward pattern (an arpeggio).  I noticed, right away, that the pattern on the left-side aid was a different pitch than the one on the right.  The right one was higher-pitched, to a degree that was noticeable, but not unpleasant.

When I mentioned it to my audiologist, she said, “no, your aids’ boot-up sounds are both exactly the same pitch.”  Huh?  So, I took the aids out and booted each of them up in the same ear.  She was right!  When I listened with just one ear, the aids’ boot-up notes were identical. Apparently, pitch distortion, or diplacusis, sometimes comes along with hearing loss. I guess that’s why I can’t sing with my church choir anymore; I was slightly off-key and never noticed, but the choir director did.