Signal processing apparatus and signal processing method

A signal processing method, comprising:

• generating a reference signal, corresponding to a target sound, based a mixed sound signal, wherein
• the mixed sound signal is recorded with multiple microphones,
• the multiple microphones are arranged at different positions, and
• the mixed sound signal is a mixture of the target sound and a non-target sound;
• and
• extracting, from the mixed sound signal of multiple frames, a signal of a first frame of the multiple frames, wherein
• the signal of the first frame is similar to the reference signal,
• the target sound is enhanced in the signal of the first frame,
• the signal of the first frame is extracted from the mixed sound signal of the multiple frames,
• the multiple frames include the first frame and a second frame, and
• the second frame is before the first frame.

A non-transitory computer-readable medium having stored thereon, computer-executable instructions which, when executed by a computer, cause the computer to execute operations, the operations comprising:

• generating a reference signal, corresponding to a target sound, based on a mixed sound signal, wherein
• the mixed sound signal is recorded with multiple microphones,
• the multiple microphones are arranged at different positions, and
• the mixed sound signal is a mixture of the target sound and a non-target sound;
• and
• extracting, from the mixed sound signal of multiple frames, a signal of a first frame of the multiple frames, wherein
• the signal of the first frame is similar to the reference signal,
• the target sound is enhanced in the signal of the first frame,
• the signal of the first frame is extracted from the mixed sound signal of the multiple frames,
• the multiple frames include the first frame and a second frame, and
• the second frame is before the first frame.

A signal processing apparatus, comprising:

• a reference signal generating section configured to generate a reference signal, corresponding to a target sound, based on a mixed sound signal, wherein
• the mixed sound signal is recorded with multiple microphones,
• the multiple microphones are arranged at different positions, and
• the mixed sound signal is a mixture of the target sound and a non-target sound;
• and
• a sound source extracting section configured to extract, from the mixed sound signal, a final signal, wherein
• the final signal is similar to the reference signal,
• the target sound is enhanced in the final signal, and
• in a case where a process of the generation of the reference signal and a process of the extraction of the final signal from the mixed sound signal are executed iteratively:
• the reference signal generating section is further configured to generate a new reference signal based on the final signal extracted at an n-th iteration from the mixed sound signal;
• and
• the sound source extracting section is further configured to extract a new final signal from the mixed sound signal based on the new reference signal, wherein the new final signal is extracted based on each of an amplitude of the new reference signal generated at an (n+1)-th iteration and a phase of the final signal extracted from the mixed sound signal at the n-th iteration.

A signal processing method, comprising:

• generating a reference signal, corresponding to a target sound, based on a mixed sound signal, wherein
• the mixed sound signal is recorded with multiple microphones,
• the multiple microphones are arranged at different positions, and
• the mixed sound signal is a mixture of the target sound and a non-target sound;
• and
• extracting, from the mixed sound signal, a final signal, wherein the final signal is similar to the reference signal, the target sound is enhanced in the final signal, and
• in a case where a process of the generation of the reference signal and a process of the extraction of the final signal from the mixed sound signal are executed iteratively;
• generating, by a signal processing apparatus, a new reference signal based on the final signal extracted at an n-th iteration from the mixed sound signal;
• and
• extracting, by the signal processing apparatus, a new final signal from the mixed sound signal based on the new reference signal, wherein the new final signal is extracted based on each of an amplitude of the new reference signal generated at an (n+1)-th iteration and a phase of the final signal extracted from the mixed sound signal at the n-th iteration.

A non-transitory computer-readable medium having stored thereon, computer-executable instructions which, when executed by a computer, cause the computer to execute operations, the operations comprising:

• generating a reference signal, corresponding to a target sound, based on a mixed sound signal, wherein
• the mixed sound signal is recorded with multiple microphones,
• the multiple microphones are arranged at different positions, and
• the mixed sound signal is a mixture of the target sound and a non-target sound;
• and
• extracting, from the mixed sound signal, a final signal, wherein
• the final signal is similar to the reference signal,
• the target sound is enhanced in the final signal, and
• in a case where a process of the generation of the reference signal and a process of the extraction of the final signal from the mixed sound signal are executed iteratively, the operations further comprising:
• generating a new reference signal based on the final signal extracted at an n-th iteration from the mixed sound signal;
• and
• extracting a new final signal from the mixed sound signal based on the new reference signal, wherein the new final signal is extracted based on each of an amplitude of the new reference signal generated at an (n+1)-th iteration and a phase of the final signal extracted from the mixed sound signal at the n-th iteration.

A signal processing apparatus, comprising:

• a reference signal generating section configured to generate a reference signal, corresponding to a target sound, based on a mixed sound signal, wherein
• the mixed sound signal is recorded with multiple microphones,
• the multiple microphones are arranged at different positions, and
• the mixed sound signal is a mixture of the target sound and a non-target sound;
• and
• a sound source extracting section configured to:
• estimate an extraction filter as a solution that optimizes an objective function, wherein the objective function includes:
• an extraction result, wherein
• the extraction result includes a specific signal which is similar to the reference signal, and
• the target sound is enhanced by the extraction filter in the specific signal;
• and
• an adjustable parameter of a sound source model, wherein
• the sound source model represents similarity between the extraction result and the reference signal, and
• the objective function reflects each of:
• the similarity between the extraction result and the reference signal, and
• independence between the extraction result and a separation result of an imaginary sound source;
• and
• extract the specific signal from the mixed sound signal based on the estimated extraction filter.

A signal processing method, comprising:

• generating a reference signal, corresponding to a target sound, based on a mixed sound signal, wherein
• the mixed sound signal is recorded with multiple microphones,
• the multiple microphones are arranged at different positions, and
• the mixed sound signal is a mixture of the target sound and a non-target sound;
• estimating an extraction filter as a solution that optimizes an objective function, wherein the objective function includes;
• an extraction result, wherein
• the extraction result includes a specific signal which is similar to the reference signal, and
• the target sound is enhanced by the extraction filter in the specific signal;
• and
• an adjustable parameter of a sound source model, wherein
• the sound source model represents similarity between the extraction result and the reference signal, and
• the objective function reflects each of the similarity between the extraction result and the reference signal and independence between the extraction result and a separation result of an imaginary sound source;
• and
• extracting the specific signal from the mixed sound signal based on the estimated extraction filter.

A non-transitory computer-readable medium having stored thereon, computer-executable instructions which, when executed by a computer, cause the computer to execute operations, the operations comprising:

• generating a reference signal, corresponding to a target sound, based on a mixed sound signal, wherein
• the mixed sound signal is recorded with multiple microphones,
• the multiple microphones are arranged at different positions, and
• the mixed sound signal is a mixture of the target sound and a non-target sound;
• estimating an extraction filter as a solution that optimizes an objective function, wherein the objective function includes:
• an extraction result, wherein
• the extraction result includes a specific signal which is similar to the reference signal, and
• the target sound is enhanced by the extraction filter in the specific signal;
• and
• an adjustable parameter of a sound source model, wherein
• the sound source model represents similarity between the extraction result and the reference signal, and
• the objective function reflects each of the similarity between the extraction result and the reference signal and independence between the extraction result and a separation result of an imaginary sound source;
• and
• extracting the specific signal from the mixed sound signal based on the estimated extraction filter.