source file: m1542.txt
Date: Fri, 2 Oct 1998 13:23:37 EDT

Subject: Re:  TUNING digest 1541

From: A440A@aol.com

Greetings, 
Paul writes:
>Actually, thinking further on it, I don't think that would even be
>possible, considering that the beats don't actually exist physically,
>but arise because of nonlinearities in the auditory system.

     Gee,  I must beg to differ, based on two experiences. 
     I recently had a buzzing problem in a piano soundboard.  It was
particularly loud in the middle bass region, and only audible at the attack
phase of the note.  This short duration usually makes extraneous noises hard
to find. 
      When I detuned a unison in that area, I did so that it would beat about
three times a second, and immediately heard the buzz in the soundboard, (later
found to be small washer), vibrate in sympathy and  emit its buzzes at the
same speed.  I take this to demonstrate variable amplitude in the physical
sense. 
   The same thing happens in an airplane when the two engines of a twin get
out of synch.  I have seen drinks and ashtrays throb with the difference
pulse.  As a tuner it makes me want to go up front and start telling people in
uniform to do something about it............
Regards, 
Ed Foote 
Precision Piano Works
Nashville, Tn.