The role of spectral contrast in the perception of stop consonants following vowels and their spectral complements

Abstract

The ability of listeners to recover speech information, despite dramatic articulatory and acoustic assimilation between adjacent speech sounds is remarkable and central to understanding perception of connected speech. In recent years, studies have revealed that, to some extent, auditory processes of spectral contrast compensate for assimilative effects of coarticulation. In the present studies, series of CV syllables varying acoustically in F2-onset frequency and perceptually from [ba] to [da] were identified either following front (e.g., [i], [e]) and back (e.g., [u], [o]) vowels or following complementary nonspeech spectra. These nonspeech stimuli were harmonic spectra in which the amplitudes of individual harmonics were the inverse of their amplitudes for those same harmonics in the vowels. A prediction of a spectral contrast account is that these complementary spectra should affect perception of following sounds in a manner complementary to that for the vowels from which they were modeled. This predicted effect was obtained. Nevertheless, one may expect that not all perceptual accommodation of coarticulation is explained by spectral contrast. In addition to these initial results, findings from experiments in which stimuli and task variables are manipulated to assess the influence of other processes will be reported. [Work supported by NIDCD DC04072.]