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R H Dye

Publications and source records attributed to R H Dye.

4 recordsLinked to original sources
PubMed1990

The combination of interaural time and intensity in the lateralization of high-frequency complex signals.

In an effort to examine the rules by which information arising from interaural differences of time (IDT) and interaural differences of intensity (IDI) is combined, d"s were measured for trains of high-frequency clicks (4000 Hz, bandpass) possessing various combinations of IDT and IDI. The number of clicks was either 1 or 8, with the interclick interval either 2 or 10 ms. A 2-IFC task was employed in which the paired values of IDT and IDI favored one side during one interval and the other side during the other interval. Data obtained with the combined cues are compared to those obtained with IDTs or IDIs alone in order to determine the degree to which processing of the two cues is done independently. Results suggest that lateralization with such stimuli is based on the sum of the temporal and intensive differences and not on independent evaluations of their separate presences.

Adult↗
PubMed1990

The combination of interaural information across frequencies: lateralization on the basis of interaural delay.

Three experiments were carried out that employed low-frequency tone complexes with interaural delays that varied across the frequency domain. In the first experiment, threshold interaural delays were measured for three-tone complexes for which one, two, or all three components were delayed. The center frequency was 750 Hz and the frequency spacing (delta f) between components was 20, 50, 100, 250, or 450 Hz. For all delta f's, the presence of two diotic components elevated the threshold interaural delays obtained for the third component relative to that obtained for a pure tone of the same frequency. In the second experiment, observers made left-right judgments regarding the direction of movement of signals for which two components were delayed by 25 microseconds to the left ear during one interval and to the right ear during the other interval, while a third component of a variable time difference was delayed to the opposite side as the tone pair. Subjects reported single intracranial images during each interval, and the data showed that interaural delays of one component to one ear could be offset by interaural delays of the other two components to the other ear. In the final experiment, threshold interaural delays were measured for five-tone complexes in which one, two, three, four, or five components were delayed. The center frequency was 750 Hz and delta f was fixed at 100 Hz. Thresholds decreased in a linear fashion as the number of delayed components increased, falling by about a factor of 5 as the number of delayed components went from one to five. These results are consistent with spectrally synthetic binaural processing, with the lateral position of intracranial images determined by a combination of interaural information across the spectrum. These effects could be brought about by a linear combination of the outputs of frequency-specific cross-correlation networks or by a wideband cross correlation of the signals at the two ears.

Attention↗
PubMed1979

Lateralization of tonal signals which have neither onsets nor offsets.

In order to ascertain the special importance of binaural cues conveyed in the transient portions of dichotic signals, thresholds for interaural differences of time (delta t) and intensity (delta I) were studied using stimuli whose onsets and offsets were masked. Intense noise was used to mask all portions of each experimental trial except for the two intervals of a two-interval, forced-choice detection task. During the intervals, the noise was turned off with decay-rise times of 10 ms. What remained were tones whose interaural phase or intensity was different for intervals one and two. Performance was compared to control conditions which used unmasked gated sinusoids. For longer durations, detection without onsets and offsets was about as good as that with no masker. For the shorter signals, detection without transients was poorer than with standard lateralization, but this is attributed to forward and backward masking which reduced the effective durations of those stimuli. The ability to detect interaural differences of time with the onsets and offsets masked was extended to conditions in which the decay times of the noise were 100 ms. Performance here was slightly worse, but not by so much as to change the basic result. This is interpreted as showing that performance with the faster decay-rise times was not a product of momentary undershoots in neural following, but depended, rather, upon a true encoding of the interaural information in the stimulus fine-structure.

Acoustic Stimulation↗