Auditory perception of rolling balls
Mark M. J. Houben, Luuk Franssen, Dik J. Hermes, Armin Kohlrausch, Berry H. Eggen · The Journal of the Acoustical Society of America · 1999
Two experiments investigating the perception of recorded sounds of rolling wooden balls are reported. In the first experiment, whether subjects can identify differences in the size of rolling wooden balls, is studied. In the second experiment, the velocity of rolling balls is varied. Real recordings of wooden balls rolling over a wooden plate were presented pairwise, with a 700-ms pause in between. The stimuli had a duration of 800 ms and were presented at equal SPL. Subjects had to decide which of the two sound examples was created by the larger (first experiment) or faster ball (second experiment) (2I2AFC procedure). The results of the first experiment show that subjects are able to identify differences in the size of rolling balls, except for the stimulus pair with the smallest relative difference in diameter of 14%. The second experiment reveals that most subjects can clearly discriminate between rolling balls with different velocities, if the relative difference exceeds about 30%. However, some subjects had difficulties in labeling the sounds correctly, resulting in percentage correct responses close to 0%. It is to be expected that labeling errors will disappear when subjects receive feedback about the correctness of their responses.