Unbalanced hearing

Thanks for those responses. I've played with the balance control on my preamp, but it doesn't work for me in a satisfying way. I use a Deqx processer, but it doesn't allow for independent channel compensation. Bojack, can the Behringer boost the treble to one channel only? Even if it could, I wonder if that would mess things up for the good ear, as you mention.
Maybe I should stick a little cotton in the good ear.

I agree that an audiogram is important for many of us. I've had two in the past five years.
I'm going to give the Behringer FBQ1502 a try. Seems like a no-brainer at $100. I'll report back with the results.