First, the observed signal f(t) is decomposed into Sk(t) and
using an auditory-motivated filterbank.
This filterbank is implemented as a constant Q gammatone filterbank, constructed with K=128, bandwidth of 60-6000 Hz, and sampling frequency of 20 kHz [8].
Next, the fundamental frequency F0(t) of the desired signal is determined using an amplitude spectrogram Sk(t)s (see Sec. 3.1).
Then, the concurrent time-frequency region of the desired signal is determined using constraints (i) and (iii) [8].
In the determined concurrent time-frequency region, Ak(t) and Bk(t) are determined from Sk(t),
,
,
and
.
Sk(t) and
are determined by using the amplitude and phase spectra defined by the wavelet transform [8].
and
are determined using constraints (ii) and (iv) (see Sec. 2.2 and 3.2).
Finally, f1(t) and f2(t) are determined from Eqs. (
) and (
), respectively.
| Regularity | Constraint |
| (i) common onset/offset | synchronous of onset/offset |
| (ii) gradualness of change | piecewise-differentiable |
| polynomial approximation | |
| (slowness) | (Kalman filtering) |
| (smoothness) | (spline interpolation) |
| (iii) harmonicity | multiples of the |
| fundamental frequency | |
| (iv) changes occurring in | correlation between the |
| the acoustic event | instantaneous amplitudes |