John Kingston

Salient pitch cues in the perception of contrastive focus

The distinction between contrastive and noncontrastive focus in English can be conveyed by the difference between a L+H* vs H* pitch accent [Pierrehumbert and Hirschberg, in Intentions in Communication, edited by Cohen et al. (MIT, Cambridge, MA, 1990)]. It is unclear, however, which acoustic properties of an F0 contour convey to a listener the occurrence of the contrastive L+H* rather than the noncontrastive H*. In these experiments, rise onset F0, peak F0, and slope were varied to see how they alone and together contribute to the contrast between a L+H* vs H* on the focused constituent. Listeners classified the stimuli as either contrastive or noncontrastive, with discourse context distinguishing the two interpretations. Peak height and slope traded in determining the category boundary between interpretations. Implications for the choice of primitives in intonational models and for compositional approaches to tune meaning are discussed. [Work supported by NIH.]

Integrality of nasalization and F1 in vowels in isolation and before oral and nasal consonants: A detection‐theoretic application of the Garner paradigm

In vowel height contrasts, tongue height and soft palate height covary. A series of vowel classification experiments examined the perceptual interactions between F1 and nasalization, the principal acoustic correlates of these articulations. Listeners classified imperfectly discriminable stimuli in the set of tasks that compose the Garner paradigm. Detection‐theoretic models applied to the data led to the conclusion that vowels, whether in isolation, before oral consonants, or before nasal consonants, display integrality of F1 and nasalization. The contrary conclusion reached by Krakow et al. [J. Acoust. Soc. Am. 83, 1146–1158 (1988)] on the basis of data from a trading relations experiment reflect a limitation of that design for studying perceptual interaction. A second experiment used an array ‘‘rotated’’ in the stimulus space to determine whether F1 and nasalization are privileged, perceptually primary dimensions. A new method for predicting classification performance for the rotated array without the a...

Skilled Readers Begin Processing Sub-phonemic Features by 80 ms during Visual Word Recognition: Evidence from ERPs

Two masked priming experiments investigated the time-course of the activation of sub-phonemic information during visual word recognition. EEG was recorded as participants read targets with voiced and unvoiced final consonants (e.g., fad and fat), preceded by nonword primes that were incongruent or congruent in voicing and vowel duration (e.g., fap or faz). Experiment 1 used a long duration mask (100 ms) between prime and target, whereas Experiment 2 used a short mask (22 ms). Phonological feature congruency began modulating the amplitude of brain potentials by 80 ms; the feature incongruent condition evoked greater negativity than the feature congruent condition in both experiments. The early onset of the congruency effect indicates that skilled readers initially activate sub-phonemic feature information during word identification. Congruency effects also appeared in the middle and late periods of word recognition, suggesting that readers use phonological representations in multiple aspects of visual word recognition.

On the internal perceptual structure of distinctive features: The [voice] contrast

Several fixed classification experiments test the hypothesis that F(1), f(0), and closure voicing covary between intervocalic stops contrasting for [voice] because they integrate perceptually. The perceptual property produced by the integration of these acoustic properties was at first predicted to be the presence of low frequency energy in the vicinity of the stop, which is considerable in [+voice] stops but slight in [-voice] stops. Both F(1) and f(0) at the edges of vowels flanking the stop were found to integrate perceptually with the continuation of voicing into the stop, but not to integrate with one another. These results indicate that the perceptually relevant property is instead the continuation of low frequency energy across the vowel-consonant border and not merely the amount of low frequency energy present near the stop. Other experiments establish that neither F(1) nor f(0) at vowel edge integrate perceptually with closure duration, which shows that only auditorily similar properties integrate and not any two properties that reliably covary. Finally, the experiments show that these acoustic properties integrate perceptually (or fail to) in the same way in non-speech analogues as in the original speech. This result indicates that integration arises from the auditory similarity of certain acoustic correlates of the [voice] contrast.

The Phonetics and Phonology of Perceptually Motivated Articulatory Covariation

This paper presents evidence that the acoustic effects of demonstrably independent articulations are integrated in the perception of vowel height and [voice] contrasts. This evidence supports two hypotheses: That, in at least some instances, articulatory covariation is perceptually motivated, and that the objects of speech perception are auditory rather than articulatory. Furthermore, it appears that perceptual integration can either increase or decrease the distinctiveness of contrasting speech sounds, so it may not only create favored patterns of articulatory covariation but also disfavored patterns. This suggests that integration is a product of general auditory mechanisms, not of mechanisms specific to speech perception.

Integrality of nasalization and F1. II. Basic sensitivity and phonetic labeling measure distinct sensory and decision-rule interactions.

In vowel perception, nasalization and height (the inverse of the first formant, F1) interact. This paper asks whether the interaction results from a sensory process, decision mechanism, or both. Two experiments used vowels varying in height, degree of nasalization, and three other stimulus parameters: the frequency region of F1, the location of the nasal pole/zero complex relative to F1, and whether a consonant following the vowel was oral or nasal. A fixed-classification experiment, designed to estimate basic sensitivity between stimuli, measured accuracy for discriminating stimuli differing in F1, in nasalization, and on both dimensions. A configuration derived by a multidimensional scaling analysis revealed a perceptual interaction that was stronger for stimuli in which the nasal pole/zero complex was below rather than above the oral pole, and that was present before both nasal and oral consonants. Phonetic identification experiments, designed to measure trading relations between the two dimensions, required listeners to identify height and nasalization in vowels varying in both. Judgments of nasalization depended on F1 as well as on nasalization, whereas judgments of height depended primarily on F1, and on nasalization more when the nasal complex was below than above the oral pole. This pattern was interpreted as a decision-rule interaction that is distinct from the interaction in basic sensitivity. Final consonant nasality had little effect in the classification experiment; in the identification experiment, nasal judgments were more likely when the following consonant was nasal.

Integrating Articulations in the Perception of Vowel Height

In vowels contrasting for height, a large number of articulations covary with tongue height, which is supposed to be the principal bearer of the contrast. However, attempts to link these covarying articulations to tongue movement physiologically have been largely unsuccessful, and the particular pattern of covariation appears to make more sense as a concerted effort to influence the perceived height of F1. The experiments reported here used the Garner interference paradigm, modified to assess the perceptual primacy of stimulus dimensions, to show that the acoustic effects of two of these covarying articulations, velum height (nasalization) and rate of vocal fold vibration (pitch) are integrated perceptually with the acoustic effects of varying tongue height. This perceptual integration suggests that the different articulations are not independently perceived, contrary to the predictions of direct realist theories of speech perception, that articulatory events covary so as to enhance each other’s perceptual effects, and that the surface phonological or initial phonetic representation of vowels might be quite richly specified (contrary to claims of phonetic underspecification).

Extrapolating from spoken to signed prosody via laboratory phonology.

Laboratory phonology tests the predictions of phonological analyses through experimental investigations of phonetic behavior. This paper describes how a laboratory phonologist might investigate three issues in the analysis of the prosody of signed languages : the internal structure,if any,of the signed syllable, the realization of lexical and phrasal prominence, and the marking of edges. The paper proposes to investigate the internal structure of the syllable by adapting a variety of psycholinguistic techniques that have been extensively used to study the phonetic packaging of phonological material in spoken languages. Phonological and phonetic arguments are presented in support of the hypothesis that signed languages will increase movement kinematics to convey phrasal and perhaps lexical prominence, and an experiment is sketched that would test this hypothesis. Finally, the paper suggests that the experimental study of the edges of sign articulations might allow a clearer choice between competing phonetic and phonological accounts of external sandhi in language in general.

On the internal perceptual structure of phonological features: The [voice] distinction

Apart from phonological features and their individual phonetic correlates, an intermediate level of structure apparently exists in which subsets of phonetic properties form perceptually coherent units, referred to here as ‘‘integrated perceptual properties.’’ The mapping between each successive level of structure is arguably many‐to‐one, elevating both redundancy and distinctiveness at the level of phonological features. For the distinctive feature [voice], a main integrated perceptual property corresponding to the [+voice] value is the presence of low‐frequency energy during or near the consonant, which may be further analyzed into at least three phonetically distinct subproperties: voicing during the consonant constriction, a low F1 near the constriction, and a low F0 in the same region. Two predictions follow if these three subproperties contribute to a single integrated perceptual property. One is that the effects on [voice] judgments of varying either a low F1 or F0 should pattern in similar ways for...

Are F0 differences after stops accidental or deliberate

Differences in F0 after stops are generally thought to be unavoidable perturbations of the rate of vocal fold vibration brought about by changes in the tension of the folds during the stop [Hombert, Ohala, and Ewan, Language 55, 37–58 (1979)]. For example, F0 is depressed after voiced stops because the folds are slackened during the closure, but elevated after voiceless stops because the folds are tensed. Recent work has shown, however, that all the mechanisms proposed to account for differences in F0 after stops are seriously flawed [Kingston, MS thesis (1985)] and, furthermore, that stops of the same phonetic type, e.g., voiceless unaspirated, can elevate F0 in one language but depress it in another [Caisse, MS thesis (1982)]. The F0 differences may therefore be introduced deliberately. to enhance the phonological contrast, rather than arising as accidental byproducts of other articulations. This possibility was tested with data from Tamil, a language which contrasts long and short stops where the long stops are predictably voiceless and the short ones are predictably voiced. Since voicing is allophonic rather than distinctive in this language, F0 differences need not appear after stops if they are deliberate. On the other hand, if the F0 differences are simply an accidental byproduct of having the folds vibrating or not, then they should appear regardless of the phonological role of vocal fold vibration. Measurements of F0 after stops in Tamil show no significant difference at the onset of vowels following the two kinds of stops, supporting the contention that F0 differences are deliberate in other languages.