SURROUND SIGNAL GENERATING DEVICE, SURROUND SIGNAL GENERATING METHOD and SURROUND SIGNAL GENERATING PROGRAM

(canceled)

A surround signal generating method to which two-channel sound signals having a left channel and a right channel are inputted, and which generates surround signals of a left channel and a right channel at least, comprising:

• a surround signal generating process which subtracts a sound signal obtained by multiplying a first gain by the inputted sound signal of the right channel from the inputted sound signal of the left channel so as to generate the surround signal of the left channel, and which subtracts a sound signal obtained by multiplying a second gain by the inputted sound signal of the left channel from the inputted sound signal of the right channel so as to generate the surround signal of the right channel;
• and
• a gain setting process which sets the first gain and the second gain so that a correlation between the surround signal of the left channel and the surround signal of the right channel which are generated by the surround signal generating process becomes a positive correlation.

A surround signal generating computer program product stored in a non-transient tangible computer-readable medium and executed by a computer, to which two-channel sound signals having a left channel and a right channel are inputted, and which generates surround signals of a left channel and a right channel at least, making the computer function as:

• a surround signal generating unit which subtracts a sound signal obtained by multiplying a first gain by the inputted sound signal of the right channel from the inputted sound signal of the left channel so as to generate the surround signal of the left channel, and which subtracts a sound signal obtained by multiplying a second gain by the inputted sound signal of the left channel from the inputted sound signal of the right channel so as to generate the surround signal of the right channel;
• and
• a gain setting unit which sets the first gain and the second gain so that a correlation between the surround signal of the left channel and the surround signal of the right channel which are generated by the surround signal generating unit becomes a positive correlation.