So, I've not (yet) had a professional hearing test. But, after years of punk rock, loud guitars, mixing sound in small clubs, and crappy theatrical intercom systems, I'm left with permanent tinnitus and hearing loss. It's my constant reminder of how much fun we had in those days. It manifests primarily in the left ear but has slowly migrated to the right over the years. From what I've been able to determine by playing sine waves in headphones and matching them to my tinnitus, it's about 4,500Hz (not sure if that's a valid methodology). I have also done informal on-line hearing tests and know I have a slump between 3kHz and 5kHz (right around where the tinnitus manifests). Surprisingly my hearing sensitivity goes back up from 4kHz to 10kHz then slowly drops off again with a limit of hearing about 13kHz. I may also have some mild hypercussus in the loss range or slightly lower. Lately I've noticed I have a sensitivity to speakers at about 4.5KHz and often feel like there's distortion in the highs. My question, or hypothesis is; could I be experiencing intermodulation distortion from a combination of the internal tinnitus and external high frequencies? I'm really no expert on hearing or IMD, so maybe it's a dumb question and all the speakers I listen to distort in the highs. Or maybe there's some other phenomenon at play. Now that I think about it, maybe I could test this by using the same sine wave at 4.5kHz and see if I notice distortion.