Method of processing a plural channel audio signal

Apparatus for processing binaural signals for subsequent reproduction at an optimum region for a listener's head, comprising:

• a left channel for receiving a left signal from a binaural pair of signals, including a branch node, a summing junction and a channel filter, and having an output coupled to reproducing or recording means;
• a right channel for receiving a left signal from a binaural pair of signals, including a branch node, a summing junction and a channel filter, and having an output coupled to reproducing or recording means;
• a first crossfeed transaural crosstalk cancellation channel connected between the branch node of the left channel and the summing junction of the right channel;
• a second crossfeed transaural crosstalk cancellation channel connected between the branch node of the left channel and the summing junction of the right channel;
• wherein each of said crossfeed transaural crosstalk cancellation channels includes a crossfeed filter and signal attenuation means, the left and right channels and the crossfeed transaural crosstalk cancellation channels being constructed and arranged relative to one another so that the signal attenuation of said signal attenuation means relative to the signals in the left and right channels is such that displacement, rotation, or displacement and rotation of a listener's head in use is permitted within said optimum region without significantly changing a binaural effect by the listener.

Apparatus for processing binaural signals, comprising:

• a left channel for receiving a left signal from a binaural pair of signals, including a branch node, a summing junction and a channel filter having a transfer function G(x, A, S), and having an output coupled to reproducing or recording means;
• a right channel for receiving a right signal from a binaural pair of signals, including a branch node, a summing junction and a channel filter having a transfer function G(x, A, S), and having an output coupled to reproducing or recording means;
• a first crossfeed channel connected between the branch node of the left channel and the summing junction of the right channel;
• and
• a second crossfeed channel connected between the branch node of the left channel and the summing junction of the right channel;
• wherein each of said crossfeed channels includes a crossfeed filter having a transfer function x(S/A) where A is a predetermined acoustic transmission function from a reproduction transducer to a far ear of a listener, S is a predetermined acoustic transmission function from a reproduction transducer to a near ear of a listener, x is a constant having a value of greater than zero and less than or equal to 0.95, and the transfer function G(x, A, S) of said channel filter is a function of x, A, and S so that, in use, there is produced an optimum region for locating the head of a listener, in which optimum region a significant amount of transaural acoustic crosstalk signals remain, thereby permitting displacement, rotation, or displacement and rotation of said head within said optimum region without significantly changing the binaural effect perceived by said listener.