DEMO_WFBT Auditory filterbanks built using filterbank tree structures
This demo shows two specific constructions of wavelet filterbank trees
using several M-band filterbanks with possibly different M (making the
thee non-homogenous) in order to approximate auditory frequency bands
and a musical scale respectively. Both wavelet trees produce perfectly
reconstructable non-redundant representations.
The constructions are the following:
1) Auditory filterbank, approximately dividing the frequency band
into intervals reminisent of the bask scale.
2) Musical filterbank, approximately dividing the freq. band into
intervals reminicent of the well-tempered musical scale.
Shapes of the trees were taken from fig. 8 and fig. 9 from the refernece.
Sampling frequency of the test signal is 48kHz as used in the article.
Figure 1: Frequency responses of the auditory filterbank.
Both axes are in logarithmic scale.
Figure 2: TF plot of the test signal using the auditory filterbank.
Figure 3: Frequency responses of the musical filterbank.
Both axes are in logarithmic scale.
Figure 4: TF plot of the test signal using the musical filterbank.
References:
F. Kurth and M. Clausen. Filter bank tree and M-band wavelet packet
algorithms in audio signal processing. Signal Processing, IEEE
Transactions on, 47(2):549--554, Feb 1999.
Package: ltfat