Signal processing method and signal processing device

A signal processing device, comprising:

• a gain controller configured to multiply at least one of M signals output from M microphones by a gain so as to equalize sound pressure levels of the M signals, the M signals representing sounds that arrive at the M microphones from a sound source located within a predetermined distance from the M microphones, M being an integer equal to or greater than two;
• a delayer configured to delay at least one of the M signals so as to resolve time discrepancies between the M signals, the time discrepancies being caused by differences in arrival time between sounds that arrive at the M microphones from the sound source;
• and
• a filtering processor configured to apply a filter to the M signals that are obtained by the gain controller and the delayer, so as to generate a signal in which a sound output from the sound source located within the predetermined distance is suppressed, wherein
• the sound source is located within the predetermined distance from a microphone included in the M microphones which is located closest to the sound source.