Kathleen K. Hodgdon
Appl. Res. Lab., State Univ., P. O. Box 30, State College, PA 16804
The intent of this research was to define and validate a statistically sound subjective presentation procedure while gathering additional information on individual preferences for sound quality in the passenger compartment of a six-cylinder car. Samples of noise spectra in the passenger compartments of four six-cylinder vehicles were recorded in both steady and accelerating modes of operation. These noise spectra were then presented in a multiple-comparison listening task to 40 individuals for subjective evaluation and ranking from most to least preferred. A nonparametric statistical analysis of the data was completed utilizing the Friedman two-way analysis of variance by ranks. The data were analyzed overall as a function of vehicle and as a function of demographic subgroups of the subjects. A retest of 20 subjects was administered approximately 1 month after initial testing to assess the reliability of the procedure. [This research was sponsored by Advanced Powertrain Engineering, Ford Motor Company.]