Sum & difference tones-highest pitches

[Steve Borgstrom]

Hi listers!

I have learned to do a good job in the highest octaves now, after 
several hundred tunings this year; I'm a new part-time tuner as of 
December '02 and have been a full-time band & orchestra director for 24 
years.

I just can't distinguish the fundamental pitch on the 3 or 4 highest 
pitches, but (I think) I'm hearing the sum and/or difference tones and 
am getting pretty good unisons, especially on the better pianos I tune.

All those years of rock 'n roll when I didn't know any better and 
didn't use hearing protection... <sad grin> I use protection now, when 
I tune and when I direct my high school band and marching band.

Does anyone else have this problem and do you use the same solution? I 
tune aurally and don't want to HAVE to get an ETD...yet... <grin>

Thanks!

Steve Borgstrom
Brooklyn Park, MN