Patent ID: 7027601

Claim:
Apparatus responsive to an audio signal comprising: a detector responsive to said audio signal; and a switch arrangement responsive to said audio signal and to control signals developed by said detector, for diverting some or all of said audio signal to a first output port adapted for connection to a directional speaker, and diverting remainder of said audio signal to a second output port adapted for connection to a diffusing speaker where said detector comprises: a filter bank, where each filter in said filter bank is responsive to said audio signal, and a plurality of detector elements, each responsive to an output signal of a different filter in said filter bank; where each detector element of said plurality of detector elements detects whether x(t−t 0 )>α·x(t), where x(t) is the envelope of said audio signal at time t, t 0 is a selected delay time, and α is a constant.