Sound Attributes of Motor Driven Devices in Automobiles

摘要

A by-product of motor-driven component operations in cars, such as power windows and seats, is highly tonal noise. While much literature has focused on quantifying the prominence of tones, how tonal prominence and loudness combine to affect annoyance is not well understood. Tones also affect soundquality in other ways; different amplitude relationships between harmonics color the sound differently andsome sounds are perceived as being bright while others are deemed dull. Tests were conducted to determinethe perceptual attributes of a set of motor-driven automobile component sounds. Fifteen subjects took part ina semantic differential test in which they rated each sound using 16 word-pairs. Factor analysis identifiedthree primary components that influenced subjects’ judgments. The first factor contributed strongly tojudgments on spectral balance related scales such as sharp - dull and damped - metallic. The second factorplayed the strongest role in the scales related to roughness: rough - smooth and coarse – refined, while thethird factor can be considered to be a strength attribute and was the dominant factor in the strong - weak andpowerful – powerless scales. Annoyance appears to be strongly influenced by factor 1 and factor 2 whereas the perception of the mechanical capability of the motor appears to be most strongly influenced by factor 3. Sharpness, Loudness, Fluctuation Strength and Roughness metrics have been evaluated in terms of their correlation to the identified factors, and current research is focused on developing mathematical models to predict the identified perceptual factors.