A Perceptual Model for Power Adjustable Steering Column Sounds

The importance of the automotive customer's perception of vehicle quality has been realized to be of utmost importance by car manufacturers. Sounds that occur within the passenger compartment can have a distinct affect on this “quality” impression. Many of these sounds originate from small DC motor driven systems within the vehicle. This study addresses the sound quality of motor driven power adjustable steering columns found in many luxury class vehicles. The primary components of this work include the subjective paired comparison evaluation of the sounds generated from these systems and the corresponding correlation to objective acoustic measures. The result is a set of perceptual regression models which showed the following: loudness level was the primary factor affecting sound quality perceptions for the telescoping, retraction, tilt up and tilt down sounds; sharpness was a secondary factor that influenced the sound quality perception of the tilt up and tilt down sounds. This model can be used to quantify future systems for quality of sound and point design engineers in the right direction in designing power adjustable steering columns that are pleasing to the customer. Also, the process outlined in this paper can be used to quantify the sound quality of other vehicle components for which no literature is available.