Hands-free operation is an important feature of many communication ter
minals such as telephones and conferencing systems. In general, the qu
ality of speech from a hands-free terminal is degraded by ambient nois
e and by acoustic echo. This paper presents some of the activities in
acoustic echo control of a CEC Esprit consortium. A short description
is given of a database collected specifically for testing acoustic ech
o cancellers and of a simple methodology for comparative evaluation of
adaptive acoustic echo control methods. Eight methods have been inves
tigated so far. Annotated bibliographies are given for each method and
comparative performance results are presented.