Number of Significant Harmonics Highest Frequency Bright Sound 6 720 Dark Sound 6 720
The sounds that the tuba produced were very difficult to distinguish as being either bright or dark. It appeared that the bright sounding tuba might have had more high end harmonics with less than 10 dB volume, but even that was tough to judge.
The data for the poor sounds is much more difficult to show in a table or other graphic form. Therefore I will describe the results.
The puffed cheeks exercises produced a much brighter sound than that produced by the more controlled bright sound experiment. It had a very poor attack including a jump to the D above the B-flat and the F below it before he found the pitch. It included 9 major overtones and a lot of fuzzy sounds in the 1200 Hz-1700 Hz area.
In the experiments done with a closed jaw, the tuba produced a large number of non-harmonic pitches in the range between 360 Hz and 1000 Hz. This came across graphically as a large block/ramp of decending harmonics rather than the normal formation which shows a series of stalagmite projections at regular intervals.
This was essentially a raucous caucophony of flatulence. There was no discernable series of overtones. Rather it was simply a ramp-like block of overtones slowly decending all the way out to 2600 Hz.