Invariant cues for place of articulation in stop consonants

Abstract

In a series of experiments, identification responses for place of articulation were obtained for synthetic stop consonants in consonant-vowel syllables with different vowels. The acoustic attributes of the consonants were systematically manipulated, the selection of stimulus characteristics being guided in part by theoretical considerations concerning the expected properties of the sound generated in the vocal tract as place of articulation is varied. Several stimulus series were generated with and without noise bursts at the onset, and with and without formant transitions following consonantal release. Stimuli with transitions only, and with bursts plus transitions, were consistently classified according to place of articulation, whereas stimuli with bursts only and no transitions were not consistently identified. The acoustic attributes of the stimuli were examined to determine whether invariant properties characterized each place of atriculation independent of vowel context. It was determined that the gross shape of the spectrum sampled at the consonantal release showed a distinctive shape for each place of articulation: a prominent midfrequency spectral peak for velars, a diffuse-rising spectrum for alveolars, and a diffuse-falling spectrum for labials. These attributes are evident for stimuli containing transitions only, but are enhanced by the presence of noise bursts at the onset.

A unified account of categorical effects in phonetic perception

“…Stop consonants have largely been found to be identified by static temporal cues like VOT for the voicing distinction (Carney et al, 1977) and dynamic spectral cues such as rapid changes in spectra at release (Stevens and Blumstein 1978), time-varying spectral features (Kewley-Port, 1983), locus equations (Sussman et al 1991), and changes in moments (Forrest et al, 1988). Vowels, at least when they are isolated without surrounding consonants, can be largely identified by the first and second formants, representing the steady state peaks of resonant energy with certain bandwidths, a static spectral cue.…”

The motor theory of speech perception revised

“…According to this theory, speech perception relies on there being at least a brief period during each speech sound when its short-time spectrum is reliably distinct from those of other speech sounds. For an initial stop in a stressed syllable, for example, this period includes the burst and the first 10 ms. after the onset of voicing (Stevens & Blumstein, 1978). That a listener is nevertheless able to identify speech sounds from which these invariant attributes have been removed is explained by the claim that, in natural speech, they are sometimes missing or distorted, so that the child must learn to make use of secondary, contextconditioned attributes, such as formant transitions, which ordinarily co-occur with the primary, invariant attributes (Cole & Scott, 1974).…”

Limb versus Speech Motor Control: A Conceptual Review

“…In speech, several studies have looked for invariants, either in the extrinsic acoustic domain (Stevens & Blumstein, 1978;Strange et al, 1983;Sussman et al, 1998), or in the intrinsic domain (Fujimura, 1986;Boë et al, 1992;Tremblay et al, 2003;Baer et al, 1988;Maeda & Honda, 1994). Analogously to what force-fields do for limb movement, perturbation paradigms have been elaborated to break down the usual associations between extrinsic (acoustics) and intrinsic (articulation) variables.…”

“…The Acoustic Invariance Theory (Stevens & Blumstein, 1978;Blumstein & Stevens, 1979), the Quantal Theory of Speech (Stevens, 1972(Stevens, , 1989, and the Adaptive Variability Theory (Lindblom, 1988(Lindblom, , 1990 basically defend the idea that the motor goals are in the auditory perception domain. Thus, in the language of motor control these theories favor extrinsic motor goals.…”