Adaptive compensation for acoustic environments using 5.1 surround sound

The paper describes new concepts in the field of area equalization within an acoustical environment. Classical approaches to this problem have used adaptive prefilters to equalize room conditions to a single point in a room (Mourjopoulos, J., 1984). It is possible by using additional speakers to create echo free areas within a room. If enough cancelling speakers are used, a perfect echo free environment should be achievable. The shows that it is possible to create an area within a room in which the echo level has been reduced by several dB using a conventional 5.1 surround sound speaker arrangement (Holman, T., 2000). Simulation work was carried out to measure the performance of the cancelling techniques. A qualitative listening test was then carried out using more realistic models and anechoic sound sources. The results from these simulations were used to evaluate the audible differences that had been achieved. Of the people who took the test, 76.5% noticed an improvement in sound quality, while 17.7% graded the cancelling techniques as being of no advantage and only 5.8% graded the system as making conditions worse.