Audio interfaces and signal processing

This paper deals with problems raised by speech and sound pick-up, processi ng and reproduction in telecommunication systems. Those problems which occu r as soon as sound and speech are involved in a communication are briefly e xplained in the introduction. Then the noise and acoustic echo cancellation problems are discussed and current techniques are presented. The remaining part of the paper is dedicated to sound reproduction techniques which aim at preserving the spatial characteristics of sound and which take into acco unt the characteristics of spatial hearing. Finally, some data about standa rdization are recalled and future applications are sketched.