Auditory Perceptual Learning Research Articles

Auditory perceptual learning of tonal patterns

Characteristics of auditory perceptual learning were investigated by monitoring improvements in the identification of tonal patterns ranging in length from 135 to 540 msec in total duration. Increasing amounts of temporal complexity were imposed by the combination of elementary 3-tone segments into sequences of two, three, or four segments, thus creating patterns of 3 to 12 tones that varied in frequency and duration. Four of 5 listeners approached asymptotic identification accuracy near 90% for the longest patterns (12 tones) after about 20 h of experience with these stimuli over several weeks of daily practice. Identification was most accurate for the initial and final portions of each pattern and poorest for the middle sections. Large individual differences among subjects were apparent in the order in which the patterns were learned and in the difficulty of the various patterns for each listener. These findings suggest differences in learning strategies or differences in the focusing of auditory attention.

Learning a “tonal” vocabulary

At the last meeting of this Society, we described the time course of learning to detect individual tonal components of a sequential pattern [Leek et al., J. Acoust. Soc. Am. Suppl. 1 71, S37 (1982)]. In this study, the investigation of auditory perceptual learning was extended to an identification task. Seven listeners were first trained to identify four 3-tone mini-patterns or “syllables,” using numbered response keys. All possible combinations of these syllables (without repetition) provided twenty-four 4-syllable “words,” which the listeners were subsequently asked to identify by naming the order of the syllables. After several weeks of daily practice, most listeners learned to correctly identify the words at 80% correct or better. Although rates of learning varied among listeners, the learning curves displayed similar characteristics. As identification became more accurate, response latencies dropped by 60%–70%, supporting subjective reports of an increasingly automatic and unitary perception of the words. An analysis of perceptual confusions and how they were resolved over time shows that some words were learned as whole units. However, many apparently were learned as concatenations of 1-, 2-, or 3-syllable units, perhaps reflecting the creation of a primitive phonological system by the listener. [Work supported by NIH.]

Time Course of Auditory Perceptual Learning

The time course of auditory perceptual learning can vary from one hour to more than a year, depending on the task, the complexity of the sounds, and the level of stimulus uncertainty under which the tasks are learned. Previous studies are reviewed which show that longer training is required to identify sounds than to discriminate between them, while the least time-consuming task is to learn to detect a sound's presence. The time course of each of these tasks is greatly extended for complex sounds compared to those for single tones. The learning of a speech-like code would thus be expected to require longer training than the employed in previous psychoacoustic research. The consequences of this fact for the exploitation of residual hearing are briefly discussed.

Visual disappearances under simplified stimulus conditions caused by auditory perceptual learning

The purpose of this investigation was to determine whether auditory experience with stimuli would produce predictable changes in disappearances of these same stimuli when later presented visually under simplified stimulation conditions. Modifications in disappearance phenomena were observed which supported the inter-modal perceptual learning hypothesis.