The Many Roads to Prominence

Boosting or inhibiting - how semantic-pragmatic and syntactic cues affect prosodic prominence relations in German

In this exploratory study, we investigate the influence of several semantic-pragmatic and syntactic factors on prosodic prominence production in German, namely referential and lexical newness/givenness, grammatical role, and position of a referential target word within a sentence. Especially in terms of the probabilistic distribution of accent status (nuclear, prenuclear, deaccentuation) we find evidence for an additive influence of the discourse-related and syntactic cues, with lexical newness and initial sentence position showing the strongest boosting effects on a target word's prosodic prominence. The relative strength of the initial position is found in nearly all prosodic factors investigated, both discrete (such as the choice of accent type) and gradient (e.g., scaling of the Tonal Center of Gravity and intensity). Nevertheless, the differentiation of prominence relations is information-structurally less important in the beginning of an utterance than near the end: The prominence of the final object relative to the surrounding elements, especially the verbal component, is decisive for the interpretation of the sentence. Thus, it seems that a speaker adjusts locally important prominence relations (object vs. verb in sentence-final position) in addition to a more global, rhythmically determined distribution of prosodic prominences across an utterance.

A chimpanzee by any other name: The contributions of utterance context and information density on word choice

An important feature of language production is the flexibility of lexical selection; producers could refer to an animal as chimpanzee, chimp, ape, she, and so on. Thus, a key question for psycholinguistic research is how and why producers make the lexical selections that they do. Information theoretic approaches have argued that producers regulate the uncertainty of the utterance for comprehenders, for example using longer words like chimpanzee if their messages are likely to be misunderstood, and shorter ones like chimp when the message is easy to understand. In this work, we test for the relative contributions of the information theoretic approach and an approach more aligned with psycholinguistic models of language production. We examine the effect on lexical selection of whole utterance-level factors that we take as a proxy for register or style in message-driven production accounts. Using a modern machine learning-oriented approach, we show that for both naturalistic stimuli and real-world corpora, producers prefer words to be longer in systematically different contexts, independent of the specific message they are trying to convey. We do not find evidence for regulation of uncertainty, as in information theoretic approaches. We offer suggestions for modification of the standard psycholinguistic production approach that emphasizes the need for the field to specify how message formulation influences lexical choice in multiword utterances.

Role of pitch in toddler looking to new and given referents in American English

This study examined how toddler looking to a discourse referent is mediated by the information status of the referent and the pitch contour of the referring expression. Eighteen-month-olds saw a short discourse of three sets of images with the proportion of looking time to a target analyzed during the final image. At test, the information status of the referent was either new or given and the referring expression was presented with one of three pitch contours (flat f0, monotonal (~H*), or bitonal (~L+H*)). In Experiment 1, toddlers looked reliably longer to a target referent when it was either new to the discourse or carried a non-flat pitch contour. In Experiment 2, the referring expression was removed to observe effects of information status alone on looking to a target referent. Toddlers looked significantly longer to a target when it was new versus given. More fine-grained time course analyses of eye movements revealed differences in the speed and duration of fixation to a target. Overall, the experiments show that discourse reference in toddlers is mediated by the presence of newness and pitch contours, even in the case of given information.

Contrast Is in the Eye of the Beholder: Infelicitous Beat Gesture Increases Cognitive Load During Online Spoken Discourse Comprehension

We investigated how two cues to contrast-beat gesture and contrastive pitch accenting-affect comprehenders' cognitive load during processing of spoken referring expressions. In two visual-world experiments, we orthogonally manipulated the presence of these cues and their felicity, or fit, with the local (sentence-level) referential context in critical referring expressions while comprehenders' task-evoked pupillary responses (TEPRs) were examined. In Experiment 1, beat gesture and contrastive accenting always matched the referential context of filler referring expressions and were therefore relatively felicitous on the global (experiment) level, whereas in Experiment 2, beat gesture and contrastive accenting never fit the referential context of filler referring expressions and were therefore infelicitous on the global level. The results revealed that both beat gesture and contrastive accenting increased comprehenders' cognitive load. For beat gesture, this increase in cognitive load was driven by both local and global infelicity. For contrastive accenting, this increase in cognitive load was unaffected when cues were globally felicitous but exacerbated when cues were globally infelicitous. Together, these results suggest that comprehenders' cognitive resources are taxed by processing infelicitous use of beat gesture and contrastive accenting to convey contrast on both the local and global levels.

Perception of Word-level Prominence in Free Word Order Language Discourse

This study examines the contribution of constituent order, prosody, and information structure to the perception of word-level prominence in Russian, a free word order language. Prominence perception is investigated through the analysis of prominence ratings of nominal words in two published narrative texts. Word-level perceived prominence ratings were obtained from linguistically naïve native speakers of Russian in two tasks: a silent prominence rating task of the read text passages, and an auditory prominence rating task of the same texts as read aloud by a native Russian speaker. Analyses of the prominence ratings reveal a greater likelihood of perceived prominence for words introducing discourse-new referents, as well as words occurring in a non-canonical sentence position, and featuring acoustic-prosodic enhancement. The results show that prosody and word order vary probabilistically in relation to information structure in read-aloud narrative, suggesting a complex interaction of prosody, word order, and information structure underlying the perception of prominence.

Repetition Reduction Revisited: The Prosody of Repeated Words in Papuan Malay

It has frequently been shown that speakers prosodically reduce repeated words in discourse. This phenomenon has been claimed to facilitate speech recognition and to be language universal. In particular, the relationship between the information value of a word in a discourse context and its prosodic prominence have been shown to correlate. However, a literature review provided in this paper reveals that most evidence comes from English, where prosodic marking of information status often coincides with repetition reduction. The current study investigates to what extent repetition reduction occurs in Papuan Malay, spoken in the western part of the island of New Guinea (Indonesia). The work on Papuan Malay prosody available to date suggests fundamental differences compared to English and other Germanic languages. An acoustic analysis is carried out on repeated words in short stories produced by native Papuan Malay speakers. The results show that upon repetition, words were shortened and produced with higher F0. In a subsequent word identification task, it was found that first and second mentions were equally intelligible. Conclusions partially confirm previous work and challenge theories on how the prosody and information value of a word are related.

Variation in /u/ fronting in the American Midwest

Previous research has suggested that a greater degree of social indexing of gender, race, and regional background is produced in linguistic contexts that promote phonetic reduction. The goal of the current study was to explore this hypothesis through an examination of the realization of an ongoing sound change in the American Midwest-/u/ fronting-as a function of four linguistic factors that contribute to phonetic reduction: lexical frequency, phonological neighborhood density, discourse mention, and speaking style. The results revealed minimal effects of the linguistic factors on the degree of /u/ fronting among talkers with greater overall advancement in the /u/ fronting change-in-progress, suggesting that the process of /u/ fronting is nearing completion among some American Midwesterners. However, the results also revealed more /u/ fronting in plain laboratory speech than in clear laboratory speech and in low-frequency, low-density words than in low-frequency, high-density words among talkers with lower overall advancement in the /u/ fronting change-in-progress. The directions of these effects are consistent with the hypothesis that social indexing is greater in reduction-promoting contexts. Further, the relative sizes of these effects suggest that speaking style contributes more to variability in social indexing than lexical properties, such as frequency and neighborhood density.

Some inferences still take time: Prosody, predictability, and the speed of scalar implicatures

Experimental pragmatics has gained many insights from understanding how people use weak scalar terms (like some) to infer that a stronger alternative (like all) is false. Early studies found that comprehenders initially interpret some without an upper bound, but later results suggest that this inference is sometimes immediate (e.g., Grodner, Klein, Carbary, & Tanenhaus, 2010). The present paper explores whether rapid inferencing depends on the prosody (i.e., summa rather than some of) or predictability of referring expressions (e.g., consistently using some to describe subsets). Eye-tracking experiments examined looks to subsets (2-of-4 socks) and total sets (3-of-3 soccer balls) following some and found early preferences for subsets in predictable contexts but not in less predictable contexts (Experiment 1 and 2). In contrast, there was no reliable prosody effect on inferencing. Changes in predictability did not affect judgments of the naturalness of some, when a discourse context was available (Experiment 3). However, predictable contexts reduced variability in speakers' descriptions of subsets and total sets (Experiment 4). Together, these results demonstrate that scalar inferences are often delayed during comprehension, but reference restriction is rapid when set descriptions can be formulated beforehand.

Using prosody to infer discourse prominence in cochlear-implant users and normal-hearing listeners

Cochlear implants (CIs) provide speech perception to adults with severe-to-profound hearing loss, but the acoustic signal remains severely degraded. Limited access to pitch cues is thought to decrease sensitivity to prosody in CI users, but co-occurring changes in intensity and duration may provide redundant cues. The current study investigates how listeners use these cues to infer discourse prominence. CI users and normal-hearing (NH) listeners were presented with sentences varying in prosody (accented vs. unaccented words) while their eye-movements were measured to referents varying in discourse status (given vs. new categories). In Experiment 1, all listeners inferred prominence when prosody on nouns distinguished categories ("SANDWICH"→not sandals). In Experiment 2, CI users and NH listeners presented with natural speech inferred prominence when prosody on adjectives implied contrast across both categories and properties ("PINK horse"→not the orange horse). In contrast, NH listeners presented with simulated CI (vocoded) speech were sensitive to acoustic differences in prosody, but did not use these cues to infer discourse status. Together, this suggests that exploiting redundant cues for comprehension varies with the demands of language processing and prior experience with the degraded signal.

The Role of Predictability in Intonational Variability

Predictability is known to affect many properties of speech production. In particular, it has been observed that highly predictable elements (words, syllables) are produced with less phonetic prominence (shorter duration, less peripheral vowels) than less predictable elements. This tendency has been proposed to be a general property of language. This paper examines whether predictability is correlated with fundamental frequency (F0) production, through analysis of experimental corpora of American English. Predictability was variously defined as discourse mention, utterance probability, and semantic focus. The results revealed consistent effects of utterance probability and semantic focus on F0, in the expected direction: less predictable words were produced with a higher F0 than more predictable words. However, no effect of discourse mention was observed. These results provide further empirical support for the generalization that phonetic prominence is inversely related to linguistic predictability. In addition, the divergent results for different predictability measures suggests that the parameterization of predictability within a particular experimental design can have significant impact on the interpretation of results, and that it cannot be assumed that two measures necessarily reflect the same cognitive reality.

Structural and Referent-Based Effects on Prosodic Expression in Russian

This study examines prosody in read productions of two published narratives by 15 Russian speakers. Two distinct sources of variation in acoustic-prosodic expression are considered: structural and referent-based. Structural effects refer to the particular linearization of words in a sentence or phrase. Referent-based effects relate to the semantic and pragmatic characteristics of the discourse referent of a word, and to grammatical roles that are partially dependent on referent characteristics. Here, we examine referent animacy and the related grammatical function of subjecthood, and the relative accessibility or information status of a word. We document patterns of prosodic augmentation and prosodic reduction due to structural and referent-based factors, as evident from change in values of acoustic-prosodic measures mean intensity, duration and f0 range. Prosodic augmentation due to structural effects is observed for words positioned ex-situ, independent of their semantic, grammatical or pragmatic features. Prosodic augmentation due to referent-based effects is observed for words that are grammatical subjects with animate referents. Prosodic expression is further affected by referent information status. Discourse-given and discourse-new information show greater prosodic augmentation than inferable information. A closer look at individual speakers' production styles reveals that structural and referent-based variations occur in combination and interact.

Reduction in Prosodic Prominence Predicts Speakers' Recall: Implications for Theories of Prosody

Repeated words are often reduced in prosodic prominence, but the underlying mechanisms remain unclear. The present study contrasted two theories: does prosodic reduction reflect the choice of a particular linguistic form, or does ease of retrieval within the language production system lead to facilitated, less prominent productions? One test of facilitation-based theories is suggested by findings on human memory: Whether a second presentation of an item benefits later memory is predicted by the item's availability at the time of the second presentation. If prosodic reduction partially reflects facilitated retrieval, it should predict later memory. One naïve participant described to another participant routes on a map. Critical items were mentioned twice. Following the map task, the speaker attempted written recall of the mentioned items. As expected, acoustic intensity of the second mentions predicted later recall in the same way that difficulty of retrieval has in other tasks. This pattern suggests that one source of prosodic reduction is facilitation within the language production system.

Synthesizing meaning and processing approaches to prosody: performance matters

Words vary in acoustic prominence; for example repeated words tend to be reduced, while focused elements tend to be acoustically prominent. We discuss two approaches to this phenomenon. On the message-based view, acoustic choices signal the speaker's meaning or pragmatics, or are guided by syntactic structure. On the facilitation-based view, reduced forms reflect facilitation of production processing mechanisms. We argue that message-based constraints correlate systematically with production facilitation. Moreover, we argue that discourse effects on acoustic reduction may be at least partially mediated by processing facilitation. Thus, research needs to simultaneously consider both competence (message) and performance (processing) constraints on prosody, specifically in terms of the psychological mechanisms underlying acoustic reduction. To facilitate this goal, we present preliminary processing models of message-based and facilitation-based approaches, and outline directions for future research.

Repetition is easy: why repeated referents have reduced prominence

The repetition and the predictability of a word in a conversation are two factors that are believed to affect whether it is emphasized: predictable, repeated words are less acoustically prominent than unpredictable, new words. However, because predictability and repetition are correlated, it is unclear whether speakers lengthen unpredictable words to facilitate comprehension or whether this lengthening is the result of difficulties in accessing a new (nonrepeated) lexical item. In this study, we investigated the relationship between acoustic prominence, repetition, and predictability in a description task. In Experiment 1, we found that repeated referents are produced with reduced prominence, even when these referents are unexpected. In Experiment 2, we found that predictability and repetition both have independent effects on duration and intensity. However, word duration was primarily determined by repetition, and intensity was primarily determined by predictability. The results are most consistent with an account in which multiple cognitive factors influence the acoustic prominence of a word.