Hi Cy, >For one thing, if I play F2 with my left hand, and hold the fork to my right ear, it's really hard to hear beats (I know I can >adjust F2 as needed for a comfortable beat speed). I found if I hold the fork over my left ear, so that it's between my ear and >the piano, the beats are clearer. (Is it because the wave interference happens in the air, not in my head? Sarah?) GREAT thread, even tho' it probably should have an "OT" beside it by now. LOL!! In answer to your question (a very good one!), it doesn't matter which routes the two sounds take; they will still beat against each other, as the waveform phasing drifts. This is actually a perceptual phenomen that occurs in the nervous system, after the sounds are detected. So however the sounds reach your ear, your still good.. Beats can of course also be observed on an oscilloscope (or on the screen of a computer displaying the waveform). However, these "beats" are merely pulsations in the waveform envelope that acoustically don't really mean anything. Now if the sounds and/or vibrations get really, really strong, to the extent that the system is no longer "linear," then that's another matter, but that's not important here. To maximize the beat, of course it is best that the two sounds be of similar amplitude -- with respect to how you *hear* them. If the fork between your teeth sound *to you* as loud as the vibrating string, then that's where you should get your loudest beat The fork between the teeth idea sounds sounds best. Isn't that where a fork belongs anyway? I'll echo the precaution from others about hard, bare metal against your teeth (vs., say, the heat shrink tubing). It *will* produce small fractures in your teeth over time. This is also a problem with lip and (especially) tongue piercings. (Ick! Ouch!) When a person talks, the stud rattles against the teeth, eventually fracturing them. It's also true that a warm fork is going to vibrate at a lower pitch. I've read on this list that some of you techs keep forks warmed by putting them inside pockets and such. If so, then holding the fork between the teeth shouldn't have much impact. If anything, it would help keep the fork warm. Hope that helps, although it sounds like you already got your answers on a more practical level. ;-) Peace, Sarah
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