As an audiologist, I hate the % too...and yet you'd be surprised how many patients ask for it, and how many doctors will just casually throw out a number.
The percentage formulas (and there are more than one) focus on speech frequencies. But they tell you nothing about the person's hearing. A mild hearing loss of 30 dB HL across frequencies would be the same percentage as a hearing loss that was normal (0 dB HL) through 1 kHz, then dropped to 50 at 2 kHz, 70 at 3 kHz, and no response above that.
It's a dumb approach...like saying that Kansas has the same terrain as the Appalachian mountains, because on average they're the same distance above sea level (don't know if that's true, just an example).
