I would speculate that the higher the fall, to some point, the faster the bubbles hit the ground. So there may be a Doppler effect within the bubble that compresses the sound more for higher falls.

Whether or not this affects enough of the sound during the bursting time is questionable. I would guess a faster advancing wall of the top of the bubble creates some higher frequency sounds. But the human ear cannot discriminate different frequencies that are too close to each other (masking in psychoacoustics).

Thus spectral analysis would have to be done. Analytically, I would speculate mass is shifted from lower to higher frequencies, across the spectrum, for higher waterfalls (up to some cutoff due to terminal velocity).

I would speculate that the higher the fall, to some point, the faster the water at the surface is pushed down as a result of the waterfall hitting the surface. So there may be a Doppler effect within the bubble that compresses the underwater sound more for higher falls.

Whether or not this affects enough of the sound during the bursting time is questionable. I would guess a faster advancing wall of the top of the bubble creates some higher frequency sounds. But the human ear cannot discriminate different frequencies that are too close to each other (masking in psychoacoustics).

Thus spectral analysis would have to be done. Analytically, I would speculate mass is shifted from lower to higher frequencies, across the spectrum, for higher waterfalls (up to some cutoff due to terminal velocity).

I would speculate that the higher the fall, to some point, the faster the bubbles hit the ground. So there may be a Doppler effect within the bubble that compresses the sound more for higher falls.

Whether or not this effects enough of the sound during the bursting time is questionable. I would guess the advancing wall of the top of the bubble creates some higher frequency sounds. But the human ear cannot discriminate different frequencies that are too close to each other (masking in psychoacoustics).

Thus spectral analysis would have to be done. Analytically, I would speculate more mass in the higher frequency range for higher waterfalls, up to some cutoff (due to terminal velocity).

I would speculate that the higher the fall, to some point, the faster the bubbles hit the ground. So there may be a Doppler effect within the bubble that compresses the sound more for higher falls.

Whether or not this affects enough of the sound during the bursting time is questionable. I would guess a faster advancing wall of the top of the bubble creates some higher frequency sounds. But the human ear cannot discriminate different frequencies that are too close to each other (masking in psychoacoustics).

Thus spectral analysis would have to be done. Analytically, I would speculate mass is shifted from lower to higher frequencies, across the spectrum, for higher waterfalls (up to some cutoff due to terminal velocity).