An overview on noise and echo reduction in hands-free applications

In the context of modern telecommunications, hands-free systems allow to ta lk in a more natural way, without handling a telephone. This leads to new p roblems which were negligible in classical telephony: the superposition of energetic noise and echo on the speech signal. To solve these problems and to provide a sufficient speech quality, a joint reduction of these perturba tions is needed. This paper presents a synthesis of solutions retained to a chieve this reduction in the context of mono-channel and two-channel observ ations.