Howling suppression device, howling suppression method, program, and integrated circuit

A howling suppression method of suppressing, via a howling suppression device, a howling component included in an input signal, said howling suppression method comprising:

• delaying the input signal so as to output the delayed signal as a reference signal;
• first processing including extracting a periodic signal component from the reference signal according to an adaptively updated filter coefficient that is adaptively updated by said first processing;
• detecting an occurrence of howling using at least a signal of the periodic signal component output in said first processing;
• and
• second processing including:
• obtaining, by a first suppression filter of the howling suppression device and according to timing based on when said detecting detects the occurrence of the howling, the filter coefficient according to which said first processing extracts the periodic signal component at a point in time when said detecting detects the occurrence of the howling;
• extracting, by the first suppression filter, the periodic signal component from the reference signal based on the obtained filter coefficient;
• and
• subtracting the periodic signal component extracted by said second processing from the input signal so as to output a signal obtained by the subtraction.

A non-transitory computer-readable recording medium having a program recorded thereon, the program for suppressing a howling component included in an input signal, the program causing a computer to execute a method comprising:

• delaying the input signal so as to output the delayed signal as a reference signal;
• first processing including extracting a periodic signal component from the reference signal according to an adaptively updated filter coefficient that is adaptively updated by said first processing;
• detecting an occurrence of howling using at least a signal of the periodic signal component output in said first processing;
• and
• second processing including:
• obtaining, by a first suppression filter and according to timing based on when said detecting detects the occurrence of the howling, the filter coefficient according to which said first processing extracts the periodic signal component at a point in time when said detecting detects the occurrence of the howling;
• extracting, by the first suppression filter, the periodic signal component from the reference signal based on the obtained filter coefficient;
• and
• subtracting the periodic signal component extracted by said second processing from the input signal so as to output a signal obtained by the subtraction.

An integrated circuit which suppresses a howling component included in an input signal, said integrated circuit comprising:

• a delay unit which delays the input signal so as to output the delayed input signal as a reference signal;
• a signal separation unit including an adaptive filter which extracts a periodic signal component from the reference signal according to an adaptively updated filter coefficient that is adaptively updated by said adaptive filter;
• a howling detection unit configured to detect an occurrence of howling using at least a signal of the periodic signal component output from the adaptive filter;
• and
• a howling suppression unit including:
• a first suppression filter which (i) obtains, according to timing based on when said howling detection unit detects the occurrence of the howling, the filter coefficient according to which said adaptive filter extracts the periodic signal component at a point in time when said howling detection unit detects the occurrence of the howling, and (ii) extracts the periodic signal component from the reference signal based on the obtained filter coefficient;
• and
• a subtractor which subtracts the periodic signal component extracted by said first suppression filter from the input signal so as to output a signal obtained by the subtraction.