Design of a Broadband Active Sound Control System

Hitherto the filtering techniques used in active sound control systems have been analogue: these are rapidly becoming obsolete because ' of their lack of stability and versatility. The microprocessor gives digitalₜechniques an edge both on grounds of convenience and economics: moreover the performance of digital filtering is far superior to that of analogue methods. An algorithm is presented which can be used to assess the optimum filter characteristics required for active sound control systems witha single degree of freedom. In the prooess the system is subjected to three random noise tests which directly yield the characteristics of the filter. The algorithm has been tried out in practical applications and shownₜo be both quick and convenient to use.