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Overview of the proposed model

First, the observed signal f(t) is decomposed into Sk(t) and $\phi_k(t)$ 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), $\phi_k(t)$, $\theta_{1k}(t)$, and $\theta_{2k}(t)$. Sk(t) and $\phi_k(t)$ are determined by using the amplitude and phase spectra defined by the wavelet transform [8]. $\theta_{1k}(t)$ and $\theta_{2k}(t)$ 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.


 
Table: Constraints corresponding to Bregman's psychoacoustical heuristic regularities.
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


next up previous
Next: Assumptions and constraints Up: AUDITORY SEGREGATION MODEL Previous: AUDITORY SEGREGATION MODEL
Masashi Unoki
2000-10-26