Abstract
Within the scope of new vehicle development, the sound quality expected by the customer is becoming a subject of growing interest. This applies to the drive unit with intake and exhaust system, as well as to components assumed to be of minor importance. Components such as door-lock systems and power-window lifters substantially contribute to the superposition governing the total noise impression of a vehicle and thus to the differentiation between competitors.
Optimum sound quality of a source is achieved by investigating the vibrational and acoustic behaviour of the entire system. Thereafter, binaural noise recordings are rated by juries in the psycho-acoustic laboratory. These subjective ratings are traced back to the psycho-acoustic characteristics, which are the basis for the definition of a sound-quality-index. The discrete steps of this process are exemplified by projects aiming to improve the door-slam noise, carried out at the Institute of Automotive Engineering, Aachen (ika) for several vehicle manufacturers.