Acoustic characteristic calibration method, acoustic characteristic calibration device, and FFT circuit

• Main Authors: SUGAWARA YUTA, SHINOTSUKA SUKEYUKI
• Format: Patent
• Language: Chinese; English
• Published: 03.04.2018
• Subjects: DEAF-AID SETS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKEACOUSTIC ELECTROMECHANICAL TRANSDUCERS; PUBLIC ADDRESS SYSTEMS

The present invention provides an acoustic characteristic calibration method, an acoustic characteristic calibration device and an FFT circuit. The acoustic characteristic calibration method is superior in at least one of improved repeatability of an inspection state, a reduced influence of a noise in calibrating an acoustic characteristic, and a reduced load in FFT arithmetic processing. A reference acoustic signal is outputted from a sound output unit (10) and inputted to a sound input unit (20) of a vehicle inspection device (2). The signal input to the sound input unit (20) is subjected toA/D conversion, and then the FFT arithmetic processing is carried out thereby to detect the frequency response characteristic of the sound input unit (20). The frequency response characteristic of the sound input unit (20) and the frequency characteristic of the reference acoustic signal are compared to determine the correction factors at each frequency. Based on the correction factors, the frequency response characteris