Sound pickup device, sound pickup method, and non-transitory computer readable recording medium storing sound pickup program

A sound pickup method performed by a computer, the sound pickup method comprising:

• correcting a difference in sensitivity among a plurality of microphone elements by multiplying an output signal of each of the plurality of microphone elements by a gain;
• detecting a voice of a speaker as a target sound;
• controlling the gain based on a result of detecting the target sound;
• and
• picking up the target sound in a boosted manner using the output signal of each of the plurality of microphone elements that is corrected, the target sound coming along a predetermined direction,
• wherein the controlling the gain is performed such that the gain is updated based on the output signal of each of the plurality of microphone elements when the voice of the speaker is detected, and the gain is not updated when the voice of the speaker is not detected,
• the correcting the difference in sensitivity is performed such that the output signal is multiplied, when the gain is updated, by the updated gain to correct the difference in sensitivity among the microphone elements, and the output signal is multiplied, when the gain is not updated, by the gain having been updated at the detection of the voice of the speaker to correct the difference in sensitivity among the microphone elements, and
• the detecting the target sound is configured to:
• determine whether an output signal from one microphone element among the plurality of microphone elements is the voice or a non-voice that is not the voice,
• determine whether a direction along which the target sound comes is a predetermined target sound direction along which the target sound enters the microphone elements, using the output signal of each of the plurality of microphone elements, the predetermined target sound direction being previously stored in a storage, and
• determine that the target sound is detected when the direction along which the target sound comes is determined to be the predetermined target sound direction that is previously stored, and the output signal from the one microphone element is determined to be the voice.

A non-transitory computer readable recording medium storing a sound pickup program for causing a computer to function as:

• a sensitivity corrector configured to correct a difference in sensitivity among a plurality of microphone elements by multiplying an output signal of each of the plurality of microphone elements by a gain;
• a target sound detector configured to detect a voice of a speaker as a target sound;
• a gain controller configured to control the gain based on a result of detection by the target sound detector;
• and
• a directivity synthesizer configured to pick up the target sound in a boosted manner using the output signal of each of the plurality of microphone elements that is corrected by the sensitivity corrector, the target sound coming along a predetermined direction,
• wherein the gain controller updates the gain based on the output signal of each of the plurality of microphone elements when the voice of the speaker is detected by the target sound detector, and does not update the gain when the voice of the speaker is not detected by the target sound detector,
• the sensitivity corrector multiplies, when the gain is updated, the output signal by the updated gain to correct the difference in sensitivity among the microphone elements, and multiplies, when the gain is not updated, the output signal by the gain having been updated at the detection of the voice of the speaker to correct the difference in sensitivity among the microphone elements, and
• the target sound detector includes:
• a voice determiner configured to determine whether an output signal from one microphone element among the plurality of microphone elements is the voice or a non-voice that is not the voice;
• a storage configured to previously store a predetermined target sound direction along which the target sound enters the plurality of microphone elements;
• a target sound direction determiner configured to determine whether a direction along which the target sound comes is the predetermined target sound direction that is previously stored, using the output signal of each of the plurality of microphone elements;
• and
• a target sound determiner configured to determine that the target sound is detected when the target sound direction determiner determines that the direction along which the target sound comes is the predetermined target sound direction that is previously stored, and the voice determiner determines that the output signal from the one microphone element is the voice.