Perceptual dimensions of fan sounds with different tonal characteristics

Abstract

Fan noise is a common tonal noise source in people's everyday life. While tonal sounds at high frequencies often contribute to annoyance, the perception and evaluation of low-frequency tones is not fully understood. In the present study, the perceptual dimensions of 24 tonal prototype fan sounds were explored using a semantic differential consisting of 21 adjective scales that were rated by 40 participants. The synthesized sounds had the same sound pressure level of 55 dB(A) but differed in fundamental frequency and spectral envelope of the embedded tonal signatures Using a factor analysis, four perceptual dimensions were found that explain 59 % of the variance. Fan sounds with a fundamental frequency of 60 Hz were rated to be more "humming" (1st dimension) and more "pleasant" (2nd dimension) but less "buzzing" and less "beeping" (3rd dimension) in comparison to sounds with higher fundamental frequencies of 180 Hz and 300 Hz. An analysis of the relationships between the adjective scales and psychoacoustic metrics show that the "humming" ratings were highly correlated to a metric describing the relative contribution of low frequencies to the overall loudness. In contrast, psychoacoustic sharpness and tonality had smaller correlation coefficients with the "humming" ratings.