The use of semantic differential scales in listening tests: A comparison between context and laboratory test conditions for the rolling sounds of office chairs

Semantic differentials are frequently used to investigate sounds from a subjective point of view. The application of semantic differentials to the case of the rolling sound of office chairs is dealt with in this study. After a preliminary selection of the semantic differentials by fifty-two participants, another ninety participants took part in a listening test and described the acoustic stimuli of two office chairs, of high and low quality, respectively, rolling over polyvinyl chloride (PVC), ceramic and wood floorings, under context and laboratory test conditions. Under laboratory condition, recorded real stimuli were presented to the listeners via headphones, or under SounBe condition. SounBe is a new tool that has recently been conceived to explore sound at an early design stage. With this method, interactions between a chair and the floor are simplified, a mechanical sound is produced of a wheel moving across a flooring tile, and the recorded stimuli are then presented to the listeners through headphones. Four 7-point Likert scale semantic differentials, related to calmness, roughness, pleasantness and annoyance, were used to collect subjective data. Objective data were instead obtained from psychoacoustic indexes. Factors such as gender and weight were found to have no effect on the subjective and objective data. The flooring factor instead resulted to have much more influence than the chair factor. No statistically significant difference was observed between the test conditions on the semantic differential scales, thus proving the compatibility between SounBe and real sounds.