  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.
