I was tinkering around with the TI under Classic99, and i have come up with the following values for the highest and lowest possible audible sounds i could get it to produce:
109.26625 & 10650.85714
1 X=[various values] 2 CALL SOUND(500,X,0) RUN
until i found either a bad value or a value i could not hear at 100% PC speaker volume.
Just thought some may find this interesting for whatever reason.