Sensory evaluation of the sound of rolling office chairs: An exploratory study for sound design

Only an infinitesimal part of the sounds from everyday objects that surround us has been designed specifically. This study has dealt with a sensory test for sounds produced by objects interacting with other objects, which can be performed during the concept design phase, where only some parts of the product can be tested. The aim of the study has been to prove the reliability of this preliminary test and compare it to the full-product test condition. The concept for an office-chair was considered, and the sound of a chair-wheel moving across flooring tiles was tested as a simplification of chair-flooring interactions. Sixty participants took part in a listening test and described the acoustic stimuli of the wheels of two office chairs, one of high quality and the other of low quality, rolling over polyvinyl chloride (PVC), ceramic and wood floorings. The listeners were asked to assign descriptors to stimuli from a list of 26 adjectives, according to a forced ordered scale. Comparisons were made with sounds from the rolling of real office chairs. The sound of wheel rolling was prevalently judged “rough” on ceramics, “dull” on PVC and “smooth” on wood, and some cross-modal audio-tactile verbal interactions between the sounds and flooring surfaces emerged. No statistically significant difference was found between the concept and full product test conditions, thus proving the efficacy of the concept sound test during the early design phase.