Schematic representations of rhythms. Rhythms consisted of sequences of 10-, 20-, or 40-ms noise bursts. (A) and (B) show target Rhythms 1 and 2. For each rhythm, the masker pattern was complementary to the target such that the combination of target and masker produced a uniform 10/s pattern. Each panel shows only one instance of each rhythm. In the actual psychophysical task, each rhythm was presented four times without interruption.
Rhythm discrimination by one listener. (A) and (B) show conditions with target located at 0° and 40°, respectively. Performance, represented by the discrimination index (d′), improved with increasing separation of target and masker. The dashed line at d′ = 1 indicates the criterion for threshold rhythm discrimination.
Distributions of rhythmic masking release (RMR) thresholds for the seven listeners of Experiment 1. Each listener is represented by two symbols, representing thresholds for maskers to the left (×) and right (○) of the target. A random horizontal offset is added to each symbol to minimize overlap. In each box, horizontal lines represent 25th, 50th, and 75th percentiles.
Comparison of RMR and minimum audible angle (MAA) for seven listeners. Three rows of panels indicate pass-band conditions, as indicated, and left and right columns of panels indicate conditions of target at 0° and 40°, respectively. Triangles indicate cases in which d′ for RMR was <1 at a 30° target/masker separation or MAA was <1 at a 20° separation. Each listener is represented in each panel by two symbols, for maskers located to the left and right of the target.
Distributions of RMR thresholds for various conditions of pass band (3 conditions in each panel) and target location. Symbols represent two data from each of seven listeners. Triangles indicate cases in which d′ was <1 for a target/masker separation of 30°. Other details of plot format are as described for Fig. 3.
Rhythm discrimination by one listener based on sound level alone. Target and masker were co-located at 0°. The three curves distinguished by symbol type represent three amounts of burst-by-burst variation in sound level as indicated. Performance generally improved with decreasing masker level (i.e., with increasing difference between target and masker levels) and was impaired by increasing level standard deviation.
Distributions of RMR thresholds for various conditions of varying level, pass band, and target location. Plot format is as described for Fig. 3.
Rhythm discrimination under headphones. The panels represent the most (A) and least (B) sensitive subject and the mean across nine listeners (C). The curves indicated by symbols represent conditions of various fixed interaural time differences. Error bars are standard errors of the means.
Distribution of RMR thresholds in the horizontal dimension for various experiment blocks and for stimuli consisting of patterns of 10 -, 20 -, or 40-ms noise bursts.
Rhythm discrimination in the vertical midline by one listener for stimuli consisting of patterns of noise bursts that were 10-ms (A), 20-ms (B), or 40-ms (C) in duration.
Summary of RMR thresholds (A) and MAAs (B) for three pass-band conditions in azimuth and three burst-duration conditions in elevation, as indicated. Plot format is as described for Fig. 3.
Article metrics loading...
Full text loading...