Can you hear this?
My Aunt teaches middle school math and on the last day of school the kids asked her if she could hear their cell phone rings. She could not hear this ringtone that they were using.(She and my parents are on the cusp of senior status and do qualify for senior discounts at some places)

I went searching for this ringtone, to see if I could hear it. My 30 something ears can still hear it (but pretty faint). While playing it the boyz were looking around the house trying to figure out which phone was ringing. Jon told me it hurt his ears.

See for yourself
Mosquito ring tone

I listened to the other sine tones on his site and hear a little, and like him my ears are sore also...It isn't loud noise either, it's just high frequency. I'm thinking these tones are probably used in brainwashing and subliminal messages...
Crazy...