Objective evaluation of subjective noise impressions

Abstract

Internal combustion engines are becoming ever more quiet. However, the more quiet an engine is overall, the more individual disturbing noise shares become conspicuous. These noise shares include diesel engine knocking, injector ticking or rattling and gear drive howling. The degree of annoyance of these disturbing noise shares cannot be adequately described by the noise level. To achieve an efficient evaluation of disturbing noise shares, acoustical characteristic values such as impulsiveness or tonality must be considered. In the research work described in this paper, characteristic values were developed for frequently complained about engine noises. These so called objective parameters rate the disturbing noises on a scale from 1 to 10. The work was carried out on behalf of the Forschungsvereinung Verbrennungskraftmaschinen e.V. (FVV) at the Institute for Internal Combustion Engines (VKA) of the Aachen University of Technology (RWTH Aachen).