Chigusa Kurumada

Is it or isn’t it: Listeners make rapid use of prosody to infer speaker meanings

A visual world experiment examined the time course for pragmatic inferences derived from visual context and contrastive intonation contours. We used the construction It looks like an X pronounced with either (a) a H(*) pitch accent on the final noun and a low boundary tone, or (b) a contrastive L+H(*) pitch accent and a rising boundary tone, a contour that can support contrastive inference (e.g., It LOOKSL+H*like a zebraL-H%… (but it is not)). When the visual display contained a single related set of contrasting pictures (e.g. a zebra vs. a zebra-like animal), effects of LOOKSL+H* emerged prior to the processing of phonemic information from the target noun. The results indicate that the prosodic processing is incremental and guided by contextually-supported expectations. Additional analyses ruled out explanations based on context-independent heuristics that might substitute for online computation of contrast.

Talker-Specific Generalization of Pragmatic Inferences based on Under- and Over-Informative Prenominal Adjective Use

According to Grice’s (1975) Maxim of Quantity, rational talkers formulate their utterances to be as economical as possible while conveying all necessary information. Naturally produced referential expressions, however, often contain more or less information than what is predicted to be optimal given a rational speaker model. How do listeners cope with these variations in the linguistic input? We argue that listeners navigate the variability in referential resolution by calibrating their expectations for the amount of linguistic signal to be expended for a certain meaning and by doing so in a context- or a talker-specific manner. Focusing on talker-specificity, we present four experiments. We first establish that speakers will generalize information from a single pair of adjectives to unseen adjectives in a speaker-specific manner (Experiment 1). Initially focusing on exposure to underspecified utterances, Experiment 2 examines: (a) the dimension of generalization; (b) effects of the strength of the evidence (implicit or explicit); and (c) individual differences in dimensions of generalization. Experiments 3 and 4 ask parallel questions for exposure to over-specified utterances, where we predict more conservative generalization because, in spontaneous utterances, talkers are more likely to over-modify than under-modify.

Prosody and Intention Recognition

Listeners face multiple challenges in mapping prosody onto intentions: The relevant intentions vary with the general context of an utterance (e.g., the speaker’s goals) and how prosodic contours are realized varies across speakers, accents, and speech conditions. We propose that listeners map acoustic information onto prosodic representations using (rational) probabilistic inference, in the form of generative models, which are updated on the fly based on the match between predictions and the input. We review some ongoing work, motivated by this framework, focusing on the “It looks like an X” construction, which, depending on the pitch contour and context, can be interpreted as “It looks like an X and it is” or “It looks like an X and it isn’t.” We use this construction to investigate the hypothesis that pragmatic processing shows the pattern of adaptation effects that is expected if the mapping of speech onto intentions involves rational inference.

Effects of distributional information on categorization of prosodic contours

Although prosody clearly affects the interpretation of utterances, the mapping between prosodic representations and acoustic features is highly variable. Listeners may in part cope with this variability by adapting to distributions of acoustic features in the input. We examined whether listeners adapt to distributional changes using the construction It looks like an X. When pronounced with an H* pitch accent on the final noun and a low boundary tone, the construction supports an affirmative interpretation (e.g., It looks like a ZEBRA [and I think it is one]). Conversely, when pronounced with a L+H* pitch accent and a rising boundary tone, it suggests a negative interpretation (e.g., It LOOKS like a zebra.... [but it is not]). Experiment 1 elicited pragmatic interpretations of resynthesized 12-step continua with these two contours as the end points. In Experiment 2, one group of listeners heard items sampled from the most ambiguous region along the continua followed by affirmative continuations (e.g., It looks like a zebra because it has stripes all over its body) and items near the contrastive endpoint followed by negative continuations (e.g., It looks like a zebra but it is actually something else). Another group heard the reverse (i.e., ambiguous items with negative continuations and non-contrastive items with affirmative continuations). The two groups of participants subsequently derived diverging interpretations for novel ambiguous items, suggesting that prosodic processing involves flexible mappings between acoustic features and prosodic representations that are meaningful in interpretation of speech.

Frequency maDDers, but phonology and formality maTTer, too.

In cases of allophonic variation, the frequency of a variant has been claimed to influence phonological representations, affecting the perception and recognition of words. For example, Connine (2004) found stronger Ganong effects in words with frequent variants (e.g., intervocalic tap in the word pretty) than in words with infrequent variants (e.g., [t] in the word pretty). Specifically, in a phoneme‐monitoring task, listeners reported more PRETTY responses when listening to a pre[D]y‐bre[D]y continuum than a pre[t]y‐bre[t]y continuum. If this bias is due to variant frequency, we might expect this effect to generalize across variants, independent of other factors (context, within‐paradigm alternations). However, a diverse set of variants and alternate explanatory factors contributing to the effect have not yet been investigated. For example, the roles of paradigm variants (e.g., baiting‐bait versus pretty‐*pret) and filler type (e.g., testing for intervocalic [t] in the context of carefully versus casually articulated fillers) might also explain these effects. This study builds on Connine (2004) and examines both paradigmatic relations and filler type across two allophonic alternations (tapping, final [t] glottalization). Ultimately, the results show that variant frequency alone is insufficient to account for this effect. An integrated theory of speech perception is proposed.