Active plus selective headset (ANC)-U.S. Patent 5,815,582
An active plus selective headset system for provision of active attenuation of broadband noise as well as speech filtering comprising a headset with reference microphones, residual microphones and speakers on each of a pair of open backed muffs and a controller means.
Claybaugh, David; Denenberg, Jeffrey N.; Busch, Ralph; and Hohman, John, "Active plus selective headset (ANC)-U.S. Patent 5,815,582" (1998). Engineering Faculty Publications. 110.
Claybaugh; David, Denenberg; Jeffrey N. , Busch; Ralph, Hohman; John. Active plus selective headset (ANC) US. #5,815,582 issued September, 1998