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

TL;DR

This paper introduces a novel approach for selecting auditory filterbank center frequencies using logarithmic scaling and consistent frequency coverage, based on a harmonic speaker model, verified with gammatone filterbanks.

Contribution

It proposes a new frequency scaling method and selection criteria for auditory filterbanks, enhancing consistency and coverage based on a harmonic speaker model.

Findings

Logarithmic frequency scaling improves filterbank coverage.

Linear ERB functions can also achieve consistent frequency coverage.

Method verified with gammatone filterbank simulations.

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.