is a vector composed of the loudspeaker signals i e s j u03c9 s l j u03c9 s l j u03c9 t c j u03c9 is a matrix representing the four filter transfer functions c ll j u03c9 c rl j u03c9 c lr j u03c9 and c rr j u03c9 and h j u03c9 is a matrix representing the four room impulse responses in the frequency domain h ll j u03c9 h rl j u03c9 h lr j u03c9 and h rr j u03c9 combining equations 5 and 6 yields from the above equation 6 it can be seen that when c j u03c9 h u2212 1 j u03c9 u00b7 e u2212 j u03c9 u03c4 7 i e the filter matrix c j u03c9 is equal to the inverse of the matrix h j u03c9 of room impulse responses in the frequency domain h u2212 1 j u03c9 plus an additionally delay u03c4 compensating at least for the acoustic delays then the signal z l j u03c9 arriving at the left ear of the listener is equal to the left input signal x l j u03c9 and the signal z r j u03c9 arriving at the right ear of the listener is equal to the right input signal x r j u03c9 wherein the signals.