title: Compensation for coarticulation reflects gesture perception, not spectral contrast.
abstract: This article reports three experiments designed to explore the basis for speech perceivers' apparent compensations for coarticulation. In the first experiment, the stimuli were members of three /da/-to-/ga/ continua hybridized from natural speech. The monosyllables had originally been produced in disyllables /ada/ and /aga/ to make Continuum 1, /alda/ and /alga/ (Continuum 2), and /arda/ and /arga/ (Continuum 3). Members of the second and third continua were influenced by carryover coarticulation from the preceding /l/ or /r/ context. Listeners showed compensation for this carryover coarticulation in the absence of the precursor /al/ or /ar/ syllables. This rules out an account in which compensation for coarticulation reflects a spectral contrast effect exerted by a precursor syllable, as previously has been proposed by Lotto, Holt, and colleagues (e.g., Lotto, Kluender, & Holt, 1997; Lotto & Kluender, 1998). The second experiment showed an enhancing effect of the endpoint monosyllables in Experiment 1 on identifications of preceding natural hybrids along an /al/-to-/ar/ continuum. That is, coarticulatory /l/ and /r/ information in /da/ and /ga/ syllables led to increased judgments of /l/ and /r/, respectively, in the precursor /al/-to-/ar/ continuum members. This was opposite to the effect, in Experiment 3, of /da/ and /ga/ syllables on preceding tones synthesized to range in frequency from approximately the ending F3 of /ar/ to the ending F3 of /al/. The enhancing, not contrastive, effect in Experiment 2, juxtaposed to the contrastive effect in Experiment 3, further disconfirms the spectral contrast account of compensation for coarticulation. A review of the literature buttresses that conclusion and provides strong support for an account that invokes listeners' attention to information in speech for the occurrence of gestural overlap.
authors.affiliation: Haskins Laboratories, New Haven, Connecticut 06511, USA. carol.fowler@haskins.yale.edu
authors.forename: Carol A
authors.initials: CA
authors.lastname: Fowler
mesh_terms: D001288:Attention; D005868:Gestures; D006801:Humans; D010700:Phonetics; D013060:Speech; D013068:Speech Production Measurement; D014796:Visual Perception