Signal processing device, signal processing method, and program for stabilizing localization of a sound image in a center direction

A signal processing device comprising:

• processing circuitry configured to:
• add input signals of audio of two channels to generate an addition signal;
• perform convolution of the addition signal and a head related impulse response (HRIR) in a center direction to generate a center convolution signal;
• perform convolution of each of the input signals and a binaural room impulse response (BRIR) to generate respective input convolution signals;
• and
• add the center convolution signal and each of the input convolution signals to generate respective output signals, wherein
• a room impulse response (RIR) included in the BRIR is adjusted so that
• more indirect sounds for which a L input signal of a left (L) channel out of the input signals is a sound source arrive from a left side than a case where only the input convolution signal is used as the output signal, and
• more indirect sounds for which a R input signal of a right (R) channel out of the input signals is a sound source arrive from a right side than a case where only the input convolution signal is used as the output signal.

A signal processing method comprising:

• adding input signals of audio of two channels to generate an addition signal;
• correcting the addition signal by performing convolution of the addition signal and a correction characteristic, so as to compensate for an amplitude characteristic of a head related impulse response (HRIR);
• performing convolution of the corrected addition signal and the HRIR in a center direction to generate a center convolution signal;
• performing convolution of each of the input signals and a binaural room impulse response (BRIR) to generate respective input convolution signals;
• and
• adding the center convolution signal and each of the input convolution signals to generate respective output signals.

A non-transitory computer readable medium storing instructions that, when executed by processing circuitry, perform a signal processing method comprising:

• adding input signals of audio of two channels to generate an addition signal;
• correcting the addition signal by performing convolution of the addition signal and a correction characteristic, so as to compensate for an amplitude characteristic of a head related impulse response (HRIR);
• performing convolution of the corrected addition signal and the HRIR in a center direction to generate a center convolution signal;
• performing convolution of each of the input signals and a binaural room impulse response (BRIR) to generate respective input convolution signals;
• and
• adding the center convolution signal and each of the input convolution signals to generate respective output signals.