PSYCHOACOUSTIC ANNOYANCE MODELS ASSESSMENT FOR AUTOMOTIVE FAN-SYSTEMS

Because of automotive electrification, fan systems previously hidden by internal combustion engines could become key contributors to the overall noise behavior. Metrics like overall Sound Pressure Level or Loudness are first order metrics enabling ranking. Yet, second order factors, that are relevant to assess annoyance, are not correctly described using a single criterion. This paper studies the applicability of various Psychoacoustic Annoyance (PA) models in an attempt to address subjective perception of sound quality. Based on pairwise comparison through a jury test with a set of 8 noises at a similar global level, the combined impact of several psychoacoustics metrics was previously determined. This computation includes a signal modulation metric, a frequency content balance and a tonal criterion. To assess this approach, the correlation for fan-system noise annoyance ranking based on its jury test is compared with several PA criteria, starting from initial Zwicker and Fastl model to later extensions including tonal contribution such as Schneider, More, Di or Cerkovnik. The low correlation between jury ranking and PA highlights that general models are not applicable to low pressure axial fans and that the dominant contribution of Loudness in PA calculation is biasing the comparison of similar SPL sounds. Regarding Cerkovnik (dedicated to small computer fans), similar poor applicability to automotive fans is highlighted through a new multi-linear regression with better correlation if the metric focusing on High Frequencies is replaced by the Loudness. The modified equation linking Loudness, Sharpness, Tonality and Roughness is very well correlated to jury tests.