Improved High Frequency Isolation and Sound Transfer Measurements on Vehicle Bodies

The need for more durable mobility has led to a rapid introduction of new electric systems on vehicles. The result of the application of electrified drivelines is a shift in noise energy from the low mid frequencies towards the upper end of the audible range. Following this, the need for higher frequency noise control and accurate measurement has grown. The measurement of the acoustic transfer or vehicle body isolation at higher frequencies poses a challenge for the diffraction, source level and omni-directionality. This paper shows an improved method that increases the accuracy of acoustic transfer function measurements from the components to the ear at high frequencies. A simulation model based on the Boundary Element Methods(BEM) has been made to analyze higher frequency behavior of noise sources during reciprocal measurements up to 12 kHz.

Some dedicated hardware was developed in combination with a new process. The simulation results have been validated by experimental test results, and application tests have been done on a full vehicle.