Allophone inspection device and inspection method thereof

A method for inspecting a driving state of a vehicle by an allophone inspection device in which a plurality of array microphones are disposed at a predetermined interval, comprising:

• a) analyzing allophone by collecting sound signals for each vehicle type and multiple option vehicles in advance, and generating reference data by quantifying through visualization and quantification;
• b) collecting sound signals while the vehicle is driving through a first array microphone and a second array microphone arranged at regular intervals;
• c) analyzing each sound signal received for the first array microphone and the second array microphone to determine allophone pattern of the sound signal for each sound field region;
• and
• d) generating a noise event and estimating a position of a sound source where noise is generated when an undefined allophone pattern in the reference data is detected;
• wherein estimating the position of the sound source includes:
• d-1) selecting a corresponding sound field region based on a correlation characteristic between sound signals received by the first array microphone and the second array microphone;
• d-2) obtaining a result value including one or more estimated points and distances according to a sound pressure intensity difference (ILD) and arrival time difference (TDoA) algorithm for each array microphone through the sound signal received in the selected sound field region;
• d-3) applying a weight according to a reliability of a result of a sound source estimation algorithm combining the ILD and TDoA corresponding to the selected sound field region to the result value of each array microphone;
• and
• d-4) estimating an estimated point having a minimum distance among the result value for each array microphone as a noise source position.