Logarithmic Frequency Scaling and Consistent Frequency Coverage for the Selection of Auditory Filterbank Center Frequencies

Abstract: This paper provides new insights into the problem of selecting filter center frequencies for the auditory filterbanks. We propose to use a constant frequency distance and a consistent frequency coverage as the two metrics that motivate the logarithmic frequency scaling and a regularized selection of center frequencies. The frequency scaling and the consistent frequency coverage have been derived based on a common harmonic speaker signal model. Furthermore, we have found that the existing linear equivalent rectangular bandwidth (ERB) function as well as any possible linear ERB approximation can also lead to a consistent frequency coverage. The results are verified and demonstrated using the gammatone filterbank.