The development of an auditory concept of speed

Forty pairs of tape-recorded car sounds were given to boys and girls (total N = 80) from kindergarten, grades two, four, and six to demonstrate an auditory concept of speed independent of visual cues. The stimulus pairs could vary on intensity, frequency, both, or not at all. The task was a verbal indication that the second car of a pair was travelling "faster," "slower," or the "same" speed. A developmental trend in ability to judge speed solely on auditory cues was found. Analyses indicated that Ss in grade two considered intensity to be relevant, and were most accurate on intensity shifts. Older Ss seemed more aware of frequency and frequency-intensity relationships, and on the whole accuracy on frequency shift trials increased across grades. However, when asked for explanations, all grades seemed to have difficulty with the frequency shifts, and in fact there were grade related increases in the use of intensity explanations on these trials. The implications for use of modalities other than the visual in speed, and other concept formation research are discussed.