Patent ID: 11894013
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Transport (Mechanical engineering)
Classification: CPC G  H  B | IPC B  G  H

Claim 3:
4. An acoustic signal processing method using an acoustic signal processing apparatus that includes processing circuitry and is installed in a vehicle,
wherein at least a sound pickup position and a sound amplification position are assumed to be present in the vehicle,
the method comprising:
a sound pickup signal level calculation step of the processing circuitry determining a level of a sound pickup signal obtained from a microphone that collects sound emitted from the sound pickup position; and
a control step of the processing circuitry performing control such that (i) when the level of the sound pickup signal is not greater than a predetermined threshold value or is less than the threshold value, an acoustic signal based on the sound pickup signal is played back from a speaker at the sound amplification position, and (ii) when the level of the sound pickup signal is greater than the threshold value or is at least the threshold value, the acoustic signal is not played back from the speaker to stop a sound amplification function in order to prevent propagating unintended sound.