Sound quality modelling of hairdryer noise

Abstract

The demand for acoustic comfort in domestic appliances increases with the rapid growth of living quality requirements. As a common domestic appliance, the hairdryer produces unwanted noise that affects comfort during working. Manufacturers make great efforts to control the hairdryer noise, e.g., reduce the sound pressure level (SPL) by increasing blades number to make the frequency of noise energy above the hearing range. This study investigated the noise discomfort of a supersonic hairdryer (SHD) and three standard hairdryers (HD). We measured and recorded hairdryer noise at all operating conditions, and generated 120 test stimuli at SPLs ranging from 60 to 72 dB(A) in 3 dB steps based on 24 sound samples. Twenty-four subjects evaluated the noise discomfort of all stimuli using the absolute magnitude estimation (AME) method. The contribution of psychoacoustic metrics, i.e. loudness, sharpness, roughness, fluctuation strength, tonality (hearing model) and articulation index, to the noise discomfort was analysed by partial correlation analysis. Hairdryer noise discomfort was dominated by loudness and significantly influenced by tonality. The sound quality models were established for SHD and HD by multiple linear regression between the discomfort and two psychoacoustic metrics, i.e., loudness and tonality. The SHD performed better in sound quality for less discomfort and interference of communication than the HD, yet the adverse effects of the ultra-high frequencies on comfort and health need further consideration.