Hearing aids: an overview of the state-of-the-art, challenges, and future trends of an interesting audio signal processing application

This paper is intended to give an overview of problems of hearing impairment and audio signal processing in hearing aids. First, the physiological requirements due to hearing impairment are explained and different hearing aid types are demonstrated. The main part of the paper is dedicated to present the different audio processing methods in modern hearing aids. Especially beamforming and noise reduction systems are focussed on. Future trends mainly address binaural directional processing. Here, an approach based on blind source separation is described.