Method and circuit arrangement for improving the quality of voice communication in hands-free telephone facilities

摘要

The invention is based on the object of combining the methods of echo cancellation and of noise reduction, known per se, with one another in such a manner that they mutually reinforce one another in the reduction of the interfering signal components. According to the invention, an estimated echo value of the received signal is generated by balancing the echo path in the echo canceller and this value is subtracted from the transmitted signal at the correct time. An estimated value of the original undisturbed voice signal generated by the noise reducer is transmitted to the echo canceller via a feedback branch and subtracted from the transmitted signal at the correct time. The solution according to the invention is preferably used in telephone networks with hands-free facilities. IMAGE