Abstract
Materials for the vehicle interior are of specific interest to the customer. They are in direct focus of the customer’s perception. The perceived quality is a function of all sensory data collected by the human perceptual system: Surfaces express design intent and craftsmanship by their visual appearance. Haptic features supervene when materials are touched. Sound is generated when fingers slide over the surface. And even smell has an influence on the perception of ambience which cannot be neglected. Thus the question arises as to what extend the specific senses contribute to the overall perception of the perceivable material quality.
In the past, most investigations focused on visual and haptic/tactile sensation by means of isolated conditions. Perceptual effects of touch sounds have been disregarded. The perceived quality of the vehicle interior, however, strongly depends on simultaneous stimulation of all senses involved. Therefore a method has been developed for a standardized generation of touch sound. It includes simulation of a realistic finger force, touch area and sliding velocity. Sounds generated on typical flat specimen of steering wheel materials have been recorded. Sounds were played back to participants under exclusive auditory conditions. The influence of loudness, further psycho-physical parameters and iconic sound features on perceived quality has been investigated. In a second experimental configuration the materials were applied upon steering wheel blanks. The combined effect of visual appearance, touch feel and sound were assessed. Tests partly included visual and auditory masking.
The results show various interactions of visual, tactile and auditory stimuli. Data identify the potential of experimental design and multi-sensory harmonization. The sound generated when fingers slide across a surface contains essential information about the nature and the quality of materials applied.
The study underlines that innovative approaches are essential to understand cross-sensory interaction in the perception of interior materials, including touch sounds. This enables systematic proceedings towards an optimum multi-sensory design.
KEYWORDS - vehicle interior, steering wheel, perceived quality, haptics, touch sound