Subject: Upside down -- Pitch perception From: Punita Singh <pgsingh(at)HOTMAIL.COM> Date: Tue, 8 Jun 1999 22:46:21 PDTDear List, Robert Zatorre's original query re: perception of direction of pitch change referred to pure tones, -- so I did not pitch in earlier. However, the issue seems to have become more complex lately, so I'd like to point out some up-down confusions for pitch, when harmonic complex tones are used. Dr. Ira Hirsh and I studied the influence of changes in spectral locus of harmonics and/or fundamental frequency on perception of change in both pitch and timbre. For F0 changes > 2% (vis. 200 Hz) subjects reliably reported the direction of F0 change as the direction of pitch change. HOWEVER, -- for pairs of tones with no F0 difference, or differences within 2%, pitch changes were still reported, in the direction of change of spectral locus... Listeners were evidently responding to the "spectral" rather than "virtual" pitch in this case (vis. Terhardt's terminology), or "hauteur brute" vs. "hauteur tonale" (vis. Risset's teminology, or to the "tone height", "spectral center of gravity", timbral "sharpness" (choose your favorite term !) So, for whatever it's worth (a couple of cents ?!), -- when dealing with complex tones, you have to keep the dual nature of pitch in mind, and be aware that the same spectral-temporal factors contributing to pitch, may also contribute to timbre. For details about our experiment and several relevant references, see: Singh, P. G. and Hirsh, I. J. (1992) " Influence of spectral locus and F0 changes on the pitch and timbre of complex tones", J. Acoust. Soc. Am. 92(5), 2650-2661. Sincerely, Punita ---------------------------------------------------------------------- Dr. Punita G. Singh, Sound Sense, 20-A Aurangzeb Rd, New Delhi 110011, India Tel: (91-11) 379-2328 / 301-4068 Fax: (91-11) 301-8743 E-mail: pgsingh(at)hotmail.com ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com