A flexible filterbank structure for extensive signal manipulations in digital hearing aids

Filterbanks for digital hearing aids must use significantly different criteria than those designed for coding applications. For digital hearing aids, the filterbank channel gains must be adjustable over a large dynamic range to compensate for the hearing loss. This adjustability violates the alias cancellation properties of critically sampled filterbanks designed for coding. This paper describes a filterbank designed exclusively for hearing aid applications. Consideration will be given to the extremely limited memory, low delay and low power requirements that must be met in a typical hearing aid application.