Re: Pitch evoked by spectral regularity (inharmonic components)

[Martin Braun <nombraun@xxxxxxxxx>]

Chen-gia Tsai wrote:

> ..... leads me to find a strange effect of pitch sensation. I wonder if
this effect can be explained by any model of pitch extraction.
.........
> These four tones can be heard in the file
http://server37.hypermart.net/berlin-music/ex/a_500.wav.
> In this file I demonstrate the pitch sensation f by pitch matching.
.....
> I also synthesized files for d = 700 Hz and d = 300 Hz. The empirical
equation seems to fail for d = 300 Hz (the last two tones).
> http://server37.hypermart.net/berlin-music/ex/a_700.wav
> http://server37.hypermart.net/berlin-music/ex/a_300.wav
>
> I cannot explain this unexpected pitch sensation and the empirical
equation .....

In your sound files you do not present pitch comparisons but melody
comparisons. After four inharmonic complex sounds, a, b, c, and d, you
present four harmonic sounds A, B, C, B.

Instead of a sound comparison a-A, b-B, c-C, d-D you present a melody
comparison abcd-ABCD. Careful listening shows that the pseudo pitches of a,
b, c, d do not match the pitches of A, B, C, D. For the sound files (2) and
(3) even the melody matching fails: up and down motions of the pseudo-pitch
melodies do not match those of the pitch melodies.

The pseudo pitches of your examples cannot be predicted by any general
formula. They are no f0 pitches, but global perceptional estimates based on
spectral power distribution. Such pseudo pitches could best be called timbre
height.


Harvey Holmes wrote:

> I believe that your observations may be well explained by Terhardt's
> virtual pitch theory,

This theory does not explain any pitch. It is anatomically and
physiologically unrealistic, and the speed of f0 perception excludes any
model of spectral pattern matching:

Patterson RD, Peters RW, Milroy R (1983) Threshold duration for melodic
pitch. In: R Klinke, W Hartmann (Eds) Hearing - Physiological Bases and
Psychophysics, Springer-Verlag, Berlin, pp. 321-325.

Martin

-------------------------------------------
Martin Braun
Neuroscience of Music
S-671 95 Klassbol
Sweden
e-mail: nombraun@telia.com
web site: http://w1.570.telia.com/~u57011259/index.htm