Jeff, fascinating stuff, not what I would have expected, but also not a result consistent with the science of sound as I know it. How can the overtones drop in pitch and not in amplitude when you record yourself from the next room? It makes sense to me that our psycho-acoustic _perception_ could be that the pitch is lower because of the change in amplitude of the overtones - what is the explanation for the change in _frequency_ of those overtones?
If I read your numbers correctly, didn't you measure both a lower frequency for the peak of each overtone _and_ a diminished amplitude for those same peaks? -S- On Wed, Jun 1, 2011 at 4:16 PM, Jeffrey S Barker <[email protected]> wrote: > I have found this discussion most interesting. Empirically (well known to > experts) pitch is lowered with distance even though theoretically > (simplistically, certainly) it should remain constant. I tried a simple > experiment to test this. I recorded myself playing an open C (third space, > or C'') on the F horn at close distance (about 2 meters) and in a different > room (about 8 meters from the recorder). I used a Zoom H2 with mic level > set to medium and record level of 100, recorded to wav format, then analyzed > the power spectrum in Audacity. The result is that the main spectral peak > for my C (concert F4, 353 Hz, according to Audacity) did not change, but > every higher overtone peak was about 5-10 cents flat. The relative > amplitude of these higher overtone peaks was not significantly changed even > though I thought I could hear a difference in tone between near and far > recordings. So, theoreticians, you are correct when referring to the > lowest, largest peak that defines the frequency of the note being played, > but you experts are also right when all of the overtones are taken into > consideration. It does seem that our perception of pitch is sensitive to > these. > > Here are my results: > > Overtone frequencies and amplitudes as reported in the Spectra window of > Audacity: > > Near (2m): Far (8m): Difference: Cents: > > F4 353 Hz 3.6dB 353Hz -16.9dB 0Hz 0 > > F5 707 Hz 5.3dB 704Hz -10.0dB -3Hz -7.4 > > C6 1061Hz -10.4dB 1057Hz -13.8dB -4Hz -6.5 > > F6 1415Hz -11.1dB 1408Hz -20.7dB -6Hz -8.6 > > A6 1765Hz -26.2dB 1760Hz -23.7dB -5Hz -4.9 > > C7 2122Hz -22.5dB 2116Hz -42.0dB -6Hz -4.9 > > D#7 2471Hz -35.5dB 2467Hz -41.5dB -4Hz -2.8 > > F7 2829Hz -29.5dB 2814Hz -48.7dB -15Hz -9.2 > > G7 3187Hz -41.1dB 3169Hz -41.1dB -18Hz -9.8 > > A7 3533Hz -45.8dB 3521Hz -46.3dB -12Hz -5.9 > > A#7 3895Hz -45.5dB 3874Hz -53.9dB -21Hz -9.0 > > C8 4250Hz -43.6dB 4228Hz -59.4dB -22Hz -9.0 > > D8 4597Hz -46.8dB 4580Hz -54.7dB -17Hz -6.4 > > D#8 4954Hz -55.0dB 4931Hz -59.4dB -23Hz -8.1 > > E8 5312Hz -61.0dB 5278Hz -64.3dB -35Hz -11.1 > > F8 5668Hz -59.8dB 5641Hz -69.9dB -27Hz -8.3 > > -- > Jeffrey S. Barker > Assoc. Prof. of Geophysics, Binghamton University > Faculty Master, Dickinson Community > (607) 777-2522 (Geology) (607) 777-2826 (Dickinson) > http://bingweb.binghamton.edu/~jbarker/ > _______________________________________________ > post: [email protected] > unsubscribe or set options at > https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/steve.freides%40gmail.com > _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
