Patent ID: 7599498

Claim:
An apparatus for producing three-dimensional (3D) sound, comprising: a determination unit for receiving a source sound file and determining whether the source sound file is mono or stereo; a mono sound spreading unit for converting the source sound into pseudo-stereo sound and performing sound spreading on the pseudo-stereo sound, if the source sound is determined to be mono by the determination unit; a stereo sound spreading unit for performing sound spreading on the source sound, if the source sound is determined to be stereo by the determination unit; a selection unit for receiving output of the mono sound spreading unit or stereo sound spreading unit, and transferring the output to headphones if the headphone reproduction has been selected as a result of selection of one from between speaker reproduction and headphone reproduction; and a 3D sound accelerator for receiving the output from the selection unit if speaker reproduction has been selected, removing crosstalk, which may occur during the speaker reproduction, and transferring the crosstalk-free output to speakers; wherein the stereo sound spreading unit adjusts the intensity of spreading by applying the following equation: L_processed=G_orig*L+(G_plus1*M1(L+R)+G_plus2*M2(L+R)+G_static1*(L+R))+(G_minus*M3(L−R)+G_static2*(L−R)) R_processed = G_orig*R+(G_plus1*M1(L+R)+G_plus2*M2(L+R)+G_static1*(L+R)) −(G_minus*M3(L−R)+G_static2*(L−R)); and wherein, L_processed and R_processed are data on which MEX processing was performed, G_orig, G_plus1, G_plus2, G_static1, G_minus and G_static2 are gains, M 1 ( ) and M 2 ( ) indicate that an MEX filter for an L+R signal was applied, and M3 indicates that an MEX filter for an L−R signal was applied.