Frequency warping and subband merging for approximating the critical bands with cosine-modulated filter banks

A novel approach to designing nonuniform cosine-modulated filter banks is presented. Frequency warping and subband merging are used together to obtain more freedom of frequency partitioning, and thus to approximate the critical bands of hearing more accurately. On the other hand, for a given accuracy, different compromises between warping strength and the number of channels can be investigated to minimize the computational complexity of the system.