Biomedical subjects

S A Shakhshaev

Publications and source records attributed to S A Shakhshaev.

4 recordsLinked to original sources

PubMed1987

[Effect of tone intensity and frequency on discrimination of the transition process of the acoustic stimulus].

The discrimination threshold for the stimulus rise time is 1.5 msec in low and middle frequency range and increases abruptly up to 5-6 msec in the range of 10-15 kHz. The threshold of detection of the square waveform depends on the stimulus duration: it is 3.5 dB at the duration over 6.5 msec. The threshold of detection of transition process drops with the rise of intensity from 10 to 40 dB, remaining constant afterwards.

Acoustic Stimulation↗

PubMed1981

[Lateralization thresholds for two-tone complexes in man with various interaural differences in stimulation].

With the aid of dichotic stimulation, one-tone signals (1 and 2 kHz) and two--tone complexes (mixture of these frequencies) were presented to subjects with interaural differences simulating shift of the sound image for azimuth angle alpha = 45 and 60 degrees in respect to situation of this image at the midline (alpha = 0 degree). At alpha = 0 degree, the lateralization threshold of the two--tone complex for interaural delay of the low-frequency component tone (1 kHz) is lesser by half than the lateralization threshold for the one--tone signal of the same frequency, whereas the lateralization threshold of the two--tone complex for interaural differences of the higher (2 kHz) tone intensity is somewhat greater than the analogous lateralization threshold for the one--tone signal of the same frequency. At alpha = 45 degrees, the differences between respective lateralization thresholds of the two--tone complex and one--tone signals become less obvious, and quite insignificant at alpha = 60 degrees.

Auditory Perception↗

PubMed1980

[Characteristic for lateralization of bitonal complexes].

In two subjects, bitonal complex with odd frequencies had the significance of lateralization threshold lesser by half of the single-tone signal threshold according to interaural time difference. In bitonal complex with even frequencies the threshold was still less which indicates a greater interaction of tones with even frequencies. Greater thresholds of lateralization were observed in bitonal complexes by interaural difference in intensities of the higher tone of the complex as compared with the same threshold for single-tone signal. Curves of the dependence of lateralization threshold of bitonal complex by interaural difference in intensities of the higher tone of the complex upon the interaural time differences of: 1) bitonal signal, 2) low-pitched tone, 3) high-pitched tone, were obtained.

Adult↗

PubMedDate not supplied

Effects of tone intensity and frequency on discrimination of the sound stimulus transition process.

In our research, we determined the dependence of human detection of differences in the sound stimulus transition process upon sound intensity and frequency. We established that the discrimination threshold for the stimulus rise time (delta tau r) is approximately 1.5 msec at low and intermediate tone frequencies and increases to 5-6 msec during an increase in frequency from 10 to 15 kHz. It was shown that the ability of a human to discriminate a stepwise change in the stimulus envelope depends upon the duration of the steps. For steps of short duration (up to 7 msec), a linear decrease in the discrimination threshold value for detecting a drop in step amplitude (delta I) occurs with increasing duration of the step (t). For a step duration greater than 7 msec, the discrimination threshold for a drop in amplitude remains constant, equaling a value on the order of 3.5 dB. It was found that the values of delta tau r and delta I rapidly decrease with an increasing level of stimulus intensity in the range of 10-40 dB and remain practically constant in the range of 40-80 dB.

Acoustic Stimulation↗