Fred,
If you go to the referenced thread, you'll see that a number of people have heard this. Strike a note solidly in Program 1 in the C3-C4 range and hold it. Because of the looping, it kicks in strongly in 1+ seconds and then very slowly decays.

I don't know what to say if you can't hear it. Maybe you are just not sensitive to these particular frequencies.

If you are interested, I suggest you go to the K2600 User Group (link above) and go through Stoph's step-by-step changes. Stoph was the only person who really put in some effort to solve the problem, and he did a terrific job. Then, compare this to the original Program 1. There is a very clear difference.

Thanks,
Mike