On the combination of systems for listening-room compensation and acoustic echo cancellation in hands-free teleconference systems

The most natural form of human communication is speech. During the last decades an increasing demand for natural and comfortable speech communication over long distances can be observed and hands-free telecommunication setups are widely used nowadays. Examples for such systems (without claim for completeness) are video-conferencing systems, hands-free front-ends in cars, information terminals, e. g. at railway stations, airports, or public places, smart homes, messaging-software like ICQ c○ or Skype c○ , or computer software and computer games with sound output and speech input. Hands-free systems can be used to increase security while driving a vehicle or to increase communication comfort in teleconference situations. By this, the user of a hands-free telecommunication system may use both hands for other tasks and/or can move freely in a room. Furthermore, the use of a hands-free setup for communication while driving a car is required mandatorily, e. g. by German law since 2001.