One can thus deduce that an electronic rather than physical means of removing any acoustic echoes is
required. In order to perform such rapid dynamic environmental adaptation, use is made of
complex mathematical algorithms, involving thousands of modelling coefficients. Considering
that the adaptation must be performed in real-time, one can conceive that a significant amount
of processing power is required to keep the modelling coefficients of the algorithm in match
with that of the environment. Tests in research labs around the world have shown very
promising results, using a range of algorithms, and with further refinement, one can soon
expect to see the availability of true hands-free communication.
The hands-free telephone problem - An annotated bibliography
Eberhard Hansler, Signal Processing 27 (1992) 259-271, 1992 Elsevier Science Publishers B.V.
Acoustic echo canceller for hands-free mobile radiotelephony
Soren Holdt Jensen, Signal Processing VI : Theories and Applications, 1992 Elsevier Science Publishers B.V.
Enhancement of hands-free telecommunications
P.Naylor, J.Alcazar, J.Boudy, Y.Grenier, Freetel project (Esprit III). ANN. TELECOMMUN., 49 no 7-8 1994.