Low commonality between tests of auditory discrimination and of speech perception

The relation between measures of speech processing and of fine auditory discrimination abilities was investigated by means of factor analyses of the performance of normal listeners on the Test of Basic Auditory Capabilities, TBAC [Watson et al., J. Acoust. Soc. Am. Suppl. 1 71, S72 (1982)]. The eight subtests of the TBAC include syllable identification in noise and discrimination of (a) changes in frequency, intensity, and duration in 1.0‐kHz sinusoids; (b) “jitter” within a pulse train; (c) temporal order for sinusoids and nonsense syllables; and (d) detection of single‐component changes in word‐length tonal patterns. Data were collected in a field (n = 127) and using earphones (n = 119). Test reliability was high in both presentation conditions. Average performance was slightly higher with earphones for discrimination of intensity, of tonal patterns, and in the two speech subtests. Both groups showed large ranges of individual performance on all subtests. Factor analyses revealed similar structures for both groups, consisting essentially of two factors loaded on the nonspeech tests (complex sound/pitch and duration/intensity) and a third that is mainly a speech factor. This result, and the associated inter‐test correlations, points towards only a very weak relation between listeners' measured abilities to hear out fine details of acoustic waveforms and their skill at identifying speech sounds. [Work supported by NIH and AFOSR.]