Advanced voice communication with acoustic echo cancelling and enhanced sound quality

The authors first consider speech coding according to CCITT-Rec. G.722, which allows an increased audio bandwidth of 7 kHz at a data rate of 64 kbit/s in the ISDN (integrated services digital network). The problem of hands-free telephony is then afforded special attention and a solution is proposed utilizing an acoustic echo canceller. The objective is to develop a compact implementation of both algorithms, using digital signal processors, which also provides for optimal determination and control of system parameters. The results are discussed and applications for future services are presented