Today’s experience with my iPhone demonstrates that I am losing the ability to hear certain tones/pitches. I was shaving, with an electric razor (buzzing noise inches from my ears) when my phone rang. I was in the bathroom, and the phone on a table next to my bed in the next room. The ringer volume was set to maximum, but I did not hear the ring. I did, however, hear the phone vibrating as it lay on the table.
I thought it was a bit odd, that I completely missed the ring-tone, but could hear the vibrating noise well enough to turn off the shaver to see where that odd buzzing was coming from.
The moral of the story? If you call me, and I don’t answer, be sure and leave a voicemail! I might simply have not heard the phone!