Characteristics of short-term memory of tone duration in the human auditory system

Information for "tone duration" (duration information) is an important parameter in representing the temporal sequence. This paper reports on the results of a basic auditory psychophysical experiment which was executed in order to estimate how information is represented in the process to be perceived and retained in the brain. The experiment focuses on the "gradual change of the retained duration information," which has been intentionally excluded in the past acoustic psychology, in order to focus on the perception process. The subject is instructed to compare the durations of two successively presented tones. The experiment demonstrated that the interval of uncertainty, which is the index of forgetting the retained information, depends on the duration of the first tone as well as the interstimulus interval between the two tones. It is then suggested that there exists a "duration which is especially easily forgotten." A result is also obtained that is consistent with the conjecture that the presented duration information is handled almost as a continuous value in the brain. It is expected that those findings will provide a clue to the modeling of temporal sequence processing in the brain.