Individual differences in vowel recognition
Steven Greenberg · The Journal of the Acoustical Society of America · 1977
Dorman et al. [Haskins Laboratories, Status Report on Speech Research SR 37/38 (1974)] observed that their experimental population could be divided into two groups on the basis of performance in a backward recognition masking paradigm. The experiments reported here attempt to resolve whether the pattern of individual differences originally reported by Dorman and colleagues derives principally from variability in (1) the rate of access to short-term verbal memory, or (2) the precision of acoustic-phonetic discrimination. Stimuli for Experiment I consisted of three synthetically generated, 24-msec vowels ([I], [ɛ], [æ]) followed at a variable interval (0–320 msec) by a vowel-like [εΓ] mask. Response patterns of individual subjects segregated into one of two discrete types, consistent with Dorman et al.'s “masker”, “nonmasker” dichotomy. However, experiment II, using four target stimuli ([I], [ɛ], [æ], [a]) and two masks ([εΓ], [o]) witnessed a significant narrowing of the performance gap between the “masker” and “nonmasker” groups, raising certain doubts about the role played by short-term verbal memory processes in the differentiation of “maskers” and “nonmaskers.” [Research supported by NSF and USPHS.]