Study On Psychoacoustic Methods Of Simultaneous Masking Threshold

Simultaneous masking which is an important research content of psychoacoustic, have a wide range of applications in audio coding, speech enhancement and so on. The research on simultaneous masking curve and pattern has been studied widely in abroad with a series of research results; while the research on this topic in our country has not been studied deeply. It is necessary to establish a complete and systematic database of simultaneous masking based on Chinese, because it can make a better understanding of the working mechanism of the human auditory system, and help to develop the audio signal processing technology of the auditory characteristics for Chinese.As a part of National Natural Science Foundation research, it needs a large number of test works with psychoacoustic experiments to establish the simultaneous masking curve database which is based on narrow-band noise masking on critical band. The purpose of this study is to find an accurate and fast experimental method to estimate the target threshold.This paper studies the response of the subjects, psychophysical methods, especially detailed studied in adaptive procedure, and experiment design in the psychoacoustic experiment. The performances of three non-parametric estimations were compared with each other through simulation and psychoacoustic experiments: transformed up-down method (UDTR), parameter estimation by sequential testing (PEST), accelerated stochastic approximation (ASA).From the above study, we have the following main conclusions:1)Estimation with forced choice tasks is more reliable than that with Yes/No tasks. 2) It is feasible to fit the psychometric function by the method of constant stimuli and study ,and to study on the psychophysics through computer simulation. 3) Compared with other two procedures, accelerated stochastic approximation (ASA) is more suitable to estimate the threshold of simultaneous masking.As an independent study, this paper made a preparatory work for measuring the threshold of simultaneous masking, and provided a valuable reference to the specific operation for a large number of experiments.