A study on vehicle exterior noise evaluation method considering building acoustic performance and sound quality

Some say that vehicle exterior noise evaluation should take into account the noise spectrum changes due to acoustic wave propagation from the vehicle to the room, and should use an index that emphasizes low frequency components rather than the A characteristic value. In this study, the validity of this opinion was examined by simultaneous measurement of indoor and outdoor noise along a suburban road, their subjective evaluation, and theoretical calculations. As a result, such facts were found. 1) When the engine speed is low, such as during mild acceleration at low speeds, the acoustic resonances in a residence room cavity due to the engine rotation order component worsens the sense of noise fluctuation. 2) Loudness has better correlation with subjective evaluation than A characteristic value. These results suggest that reconsideration of the vehicle driving conditions and the evaluation indices for motor vehicle exterior tests, and the acoustic performance standards of the building are expected.