An objective and subjective study on global active control of engine noise in a car

The work tests and analyzes the engine noise distribution in a car with and without active control, where the car’s built-in loudspeakers are used as secondary sources to attenuate the engine noise inside the whole cabin. To analyze the sound field in detail, the noise level at 52 microphones on the passenger ears’ plane is measured and presented. The distributions of the primary overall noise, first four order noise of the engine, and the sound field generated by the subwoofer at engine orders’ frequencies are reported, and the noise reductions corresponding to overall engine noise and each order’s noise are analyzed. Besides, jury test is presented and compared with the calculated loudness of residual noise to evaluate the acoustic comfort improvement of the system. The experiment results show that the overall noise reduction is achieved inside the whole cabin by controlling the first four orders’ engine noise. The average noise reduction of the measurement area inside the cabin is 6.2 dB and 2.9 dBA. Besides, 93% of the participants feel the acoustic comfort is improved with the active noise control system on.