[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
AW: lopsided tones.
My guess is that you start out with a pure-tone sound-pressure
function of the form
p(t) = p_0 * sin(omega*t) , where omega = 2pi * 100 s^-1 ;
then you multiply all positive sound-pressure values by a factor
of (1 + epsilon), e.g., by a factor of 1.3 . Fourier analysis then
will yield a positive time-independent component, plus a large
100-hertz component, A_1 * sin(omega*t), plus many small
components of n*100 hertz, where n = 2, 3, 4, ... ; there will also
be terms of the form B_1 * cos(omega*t) and B_n * cos(n*omega*t).
Dr. phil. nat.,
r. PSI and ETH Zurich,
Phone: 0041 56 441 77 72.
Mobile: 0041 79 754 30 32.
E-mail: reinifrosch@xxxxxxxxxx .
Datum: 17.08.2009 21:41
Betreff: lopsided tones.
I have been experimenting with a 100hz tone, where the positive half
sinusoid of the period is larger than the negative, the phase is however
is not changed. Speech seems to have this profile of larger positive
pulses as compared to the negative, hence my interest. Applying fft to
such a signal, I get an increase in magnitude for the 100hz component,
and an increase in the dc component. What I hear however is the basic
100hz tone, and a flutter on top of it, not what fft seems to indicate.
My assumption was that the increased dc component would not be heard,
and I would hear an increase in loudness of the 100 hz. However, the
base 100hz loudness does not seem to change as I increase the area under
the positive sinusoid, but the flutter does. Any history or explanation
would be most welcome.
Thanks and regards,