Methods for product sound design: a correlation between annoyance and sound quality of noise emitted by household appliances

The sound of a product is now a product parameter that needs the same attention as its concept design. However it is often not known how the subjective assessments and the human factor are taken into account in the procedure governing the studies of sound quality. This case study show how the consumer perception of product sound quality is a fundamental variable to define the sound character. Psychoacoustic metrics like Loudness, Sharpness and Roughness, and the combinations of them into more sophisticated models, like annoyance, pleasantness and powerfulness were used for analysis and prediction of kitchen range hoods sound quality. However, some problems arise when the sounds are analyzed by different consumers. It is assumed that the reason for this is the human not ability to understand the difference between noise and annoyance and to focus consciously or unconsciously on the sound emitted by the appliance. For this reason, the aim of this work is to validate a method for predicting the sound quality produced by five range hoods under reals installation conditions. This was achieved by constructing a series of listening tests suitable for the case study and correlating the sound quality index with perceptual annoyance, to quantify the degree of disturbance obtained in psychoacoustic experiments.