Sound inspection apparatus and sound inspection method

A sound inspection apparatus comprising:

• a vibration sound source configured to radiate a vibration sound from a speaker to an inspection target object;
• at least four microphones arranged at intervals in a direction along a surface of the inspection target object, the microphones including a first microphone adjacent to the speaker, a second microphone arranged at an interval wider than the first microphone to the speaker, a third microphone arranged at an interval wider than the second microphone to the speaker, and a fourth microphone arranged at an interval wider than the third microphone to the speaker;
• a removing unit configured to calculate an impulse response between the first microphone and the second microphone based on a sound pressure of a radiation sound collected via the first microphone and a sound pressure of a radiation sound collected via the second microphone, calculate an impulse response between the first microphone and the third microphone based on the sound pressure of the radiation sound collected via the first microphone and a sound pressure of a radiation sound collected via the third microphone, and remove a component corresponding to the vibration sound from the calculated impulse response between the first microphone and the third microphone, and further calculate an impulse response between the second microphone and the third microphone based on the sound pressure of the radiation sound collected via the second microphone and the sound pressure of the radiation sound collected via the third microphone, calculate an impulse response between the second microphone and the fourth microphone based on the sound pressure of the radiation sound collected via the second microphone and a sound pressure of a radiation sound collected via the fourth microphone, and remove a component corresponding to the vibration sound from the calculated impulse response between the second microphone and the fourth microphone;
• an intensity calculation unit configured to calculate an intensity of the radiation sound based on the impulse response from which the vibration sound is removed;
• and
• an estimation unit configured to estimate, based on the calculated intensity, a site where an abnormality in the inspection target object has occurred.

A method applied to a sound inspection apparatus including a vibration sound source configured to radiate a vibration sound from a speaker to an inspection target object, and at least three microphones arranged at intervals in a direction along a surface of the inspection target object, the method comprising:

• using some microphones of the microphones as reference microphones, calculating an impulse response between the reference microphone and a first microphone different from the reference microphone based on a sound pressure of a radiation sound collected via the reference microphone and a sound pressure of a radiation sound collected via the first microphone, calculating an impulse response between the reference microphone and a second microphone different from the first microphone based on the sound pressure of the radiation sound collected via the reference microphone and a sound pressure of a radiation sound collected via the second microphone, and removing a component corresponding to the vibration sound from the calculated impulse response;
• calculating an intensity of the radiation sound based on the impulse response from which the vibration sound is removed;
• and
• estimating, based on the calculated intensity, a site where an abnormality in the inspection target object has occurred.

A method applied to a sound inspection apparatus including a vibration sound source configured to radiate a vibration sound from a speaker to an inspection target object, and at least four microphones arranged at intervals in a direction along a surface of the inspection target object, the microphones including a first microphone adjacent to the speaker, a second microphone arranged at an interval wider than the first microphone to the speaker, a third microphone arranged at an interval wider than the second microphone to the speaker, and a fourth microphone arranged at an interval wider than the third microphone to the speaker, the method comprising:

• calculating an impulse response between the first microphone and the second microphone based on a sound pressure of a radiation sound collected via the first microphone and a sound pressure of a radiation sound collected via the second microphone, calculating an impulse response between the first microphone and the third microphone based on the sound pressure of the radiation sound collected via the first microphone and a sound pressure of a radiation sound collected via the third microphone, and removing a component corresponding to the vibration sound from the calculated impulse response between the first microphone and the third microphone, and further calculating an impulse response between the second microphone and the third microphone based on the sound pressure of the radiation sound collected via the second microphone and the sound pressure of the radiation sound collected via the third microphone, calculating an impulse response between the second microphone and the fourth microphone based on the sound pressure of the radiation sound collected via the second microphone and a sound pressure of a radiation sound collected via the fourth microphone, and removing a component corresponding to the vibration sound from the calculated impulse response between the second microphone and the fourth microphone;
• calculating an intensity of the radiation sound based on the impulse response from which the vibration sound is removed;
• and
• estimating, based on the calculated intensity, a site where an abnormality in the inspection target object has occurred.