Why are repeated words produced with reduced durations? Evidence from inner speech and homophone production

It's Mine, . . . It's Mine: Unsolicited Repetitions Are Reduced in Toddlers

A phenomenon called "repetition reduction" can increase articulation rate in adults by facilitating phonetic and motor processes, which indicates flexibility in the control of articulation rate. Young children, who speak much slower, may not have the same speech motor flexibility resulting in the absence of the repetition reduction effect. In this study, we tested whether spontaneous repetitions of young children are produced with a faster articulation rate than their original utterances. Twelve monolingual English-speaking children were observed at four time points between 2;0 and 3;0 years of age. A significant increase in articulation rate and syllable count was found using multilevel models for all utterances over the 1-year period. At each time point, however, the repeated utterances were produced significantly faster than the original utterances even though the content and syllable count differed minimally. Our findings conform to the pattern of adult studies suggesting that a "naturistic" form of repetition reduction is already present in the speech of children at 2;0 years. Although certain aspects of speech motor control are undergoing rapid development, existing motor capability at 2;0 already supports flexible changes in articulation rate including repetition reduction.

Effects of delay, length, and frequency on onset RTs and word durations: Articulatory planning uses flexible units but cannot be prepared

There is debate regarding whether most articulatory planning occurs offline (rather than online) and whether the products of off-line processing are stored in a separate articulatory buffer until a large enough chunk is ready for production. This hypothesis predicts that delayed naming conditions should reduce not only onset RTs but also word durations because articulatory plans will be buffered and kept ready. We have tested this hypothesis with young control speakers, an aphasic speaker , and an age and education-matched speaker, using repetition, reading and picture-naming tasks. Contrary to the off-line hypothesis, delayed conditions strongly reduced onset RTs, but had no benefit for word durations. In fact, we found small effects in the opposite direction. Moreover, frequency and imageability affected word durations even in delayed conditions, consistent with articulatory processing continuing on-line. The same pattern of results was found in CS and in control participants, strengthening confidence in our results. There is debate regarding whether most articulatory planning occurs offline (rather than online) and whether the results of off-line processing are stored in a separate articulatory buffer until a large enough chunk is ready for production. This hypothesis predicts that delayed naming conditions should reduce not only onset RTs but also word durations because articulatory plans will be buffered and kept ready. We have tested young control speakers, an aphasic speaker, and an age and education matched speaker, using repetition, reading and picture naming tasks. Contrary to the off-line hypothesis, delayed conditions strongly reduced onset RTs, but had no benefit for word durations. In fact, we found small effects in the opposite direction. Moreover, frequency and imageability affected word durations even in delayed conditions, consistent with articulatory processing continuing on-line. The same pattern of results was found in CS and in control participants, strengthening confidence in our results.

Evidence of Absence: Abstract Metrical Structure in Speech Planning

Rhythmic structure in speech is characterized by sequences of stressed and unstressed syllables. A large body of literature suggests that speakers of English attempt to achieve rhythmic harmony by evenly distributing stressed syllables throughout prosodic phrases. The question remains as to how speakers plan metrical structure during speech production and whether it is planned independently of phonemes. To examine this, we designed a tongue twister task consisting of disyllabic word pairs with overlapping phonological segments and either matching or non-matching metrical structure. Results showed that speakers had more difficulty producing metrically regular word pairs, compared to irregular pairs; that is, word pairs with irregular meter had faster productions and fewer speech errors in this production task. This finding of metrical regularity inhibiting production is inconsistent with an abstract metrical structure that is planned independently of phonemes at the point of phonological encoding.

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.

Prosody indexes both competence and performance

Prosody is an important feature of language that conveys a wide range of information. However, prosody is widely considered to be a difficult domain of study within the language sciences. One consequence of this is that existing grammatical theories of prosody fail to explain prosodic choices that seem to arise from nonlinguistic cognitive demands, such as communicative context, top-down expectations, and recent articulatory and acoustic experience. We provide an account of some of these phenomena and argue that linguistic theories that do not incorporate these factors into models of prosody are likely to mischaracterize its role in language. This article is categorized under: Linguistics > Language in Mind and Brain Psychology > Language Linguistics > Linguistic Theory.

Masking auditory feedback does not eliminate repetition reduction

Repetition reduces word duration. Explanations of this process have appealed to audience design, internal production mechanisms, and combinations thereof (e.g. Kahn & Arnold, 2015). Jacobs, Yiu, Watson, and Dell (2015) proposed the auditory feedback hypothesis, which states that speakers must hear a word, produced either by themselves or another speaker, in order for duration reduction on a subsequent production. We conducted a strong test of the auditory feedback hypothesis in two experiments, in which we used masked auditory feedback and whispering to prevent speakers from hearing themselves fully. Both experiments showed that despite limiting the sources of normal auditory feedback, repetition reduction was observed to equal extents in masked and unmasked conditions, suggesting that repetition reduction may be supported by multiple sources, such as somatosensory feedback and feedforward signals, depending on their availability.

The influence of lexical selection disruptions on articulation

Interactive models of language production predict that it should be possible to observe long-distance interactions; effects that arise at one level of processing influence multiple subsequent stages of representation and processing. We examine the hypothesis that disruptions arising in nonform-based levels of planning-specifically, lexical selection-should modulate articulatory processing. A novel automatic phonetic analysis method was used to examine productions in a paradigm yielding both general disruptions to formulation processes and, more specifically, overt errors during lexical selection. This analysis method allowed us to examine articulatory disruptions at multiple levels of analysis, from whole words to individual segments. Baseline performance by young adults was contrasted with young speakers' performance under time pressure (which previous work has argued increases interaction between planning and articulation) and performance by older adults (who may have difficulties inhibiting nontarget representations, leading to heightened interactive effects). The results revealed the presence of interactive effects. Our new analysis techniques revealed these effects were strongest in initial portions of responses, suggesting that speech is initiated as soon as the first segment has been planned. Interactive effects did not increase under response pressure, suggesting interaction between planning and articulation is relatively fixed. Unexpectedly, lexical selection disruptions appeared to yield some degree of facilitation in articulatory processing (possibly reflecting semantic facilitation of target retrieval) and older adults showed weaker, not stronger interactive effects (possibly reflecting weakened connections between lexical and form-level representations). (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Variation in the speech signal as a window into the cognitive architecture of language production

The pronunciation of words is highly variable. This variation provides crucial information about the cognitive architecture of the language production system. This review summarizes key empirical findings about variation phenomena, integrating corpus, acoustic, articulatory, and chronometric data from phonetic and psycholinguistic studies. It examines how these data constrain our current understanding of word production processes and highlights major challenges and open issues that should be addressed in future research.

The role of linguistic experience in the processing of probabilistic information in production

Speakers track the probability that a word will occur in a particular context and utilize this information during phonetic processing. For example, content words that have high probability within a discourse tend to be realized with reduced acoustic/articulatory properties. Such probabilistic information may influence L1 and L2 speech processing in distinct ways (reflecting differences in linguistic experience across groups and the overall difficulty of L2 speech processing). To examine this issue, L1 and L2 speakers performed a referential communication task, describing sequences of simple actions. The two groups of speakers showed similar effects of discourse-dependent probabilistic information on production, suggesting that L2 speakers can successfully track discourse-dependent probabilities and use such information to modulate phonetic processing.

Effects of Word Frequency and Transitional Probability on Word Reading Durations of Younger and Older Speakers

High-frequency units are usually processed faster than low-frequency units in language comprehension and language production. Frequency effects have been shown for words as well as word combinations. Word co-occurrence effects can be operationalized in terms of transitional probability (TP). TPs reflect how probable a word is, conditioned by its right or left neighbouring word. This corpus study investigates whether three different age groups-younger children (8-12 years), adolescents (12-18 years) and older (62-95 years) Dutch speakers-show frequency and TP context effects on spoken word durations in reading aloud, and whether age groups differ in the size of these effects. Results show consistent effects of TP on word durations for all age groups. Thus, TP seems to influence the processing of words in context, beyond the well-established effect of word frequency, across the entire age range. However, the study also indicates that age groups differ in the size of TP effects, with older adults having smaller TP effects than adolescent readers. Our results show that probabilistic reduction effects in reading aloud may at least partly stem from contextual facilitation that leads to faster reading times in skilled readers, as well as in young language learners.

Dynamically adapted context-specific hyper-articulation: Feedback from interlocutors affects speakers' subsequent pronunciations

We ask whether speakers can adapt their productions when feedback from their interlocutors suggests that previous productions were perceptually confusable. To address this question, we use a novel web-based task-oriented paradigm for speech recording, in which participants produce instructions towards a (simulated) partner with naturalistic response times. We manipulate (1) whether a target word with a voiceless plosive (e.g., pill) occurs in the presence of a voiced competitor (bill) or an unrelated word (food) and (2) whether or not the simulated partner occasionally misunderstands the target word. Speakers hyper-articulated the target word when a voiced competitor was present. Moreover, the size of the hyper-articulation effect was nearly doubled when partners occasionally misunderstood the instruction. A novel type of distributional analysis further suggests that hyper-articulation did not change the target of production, but rather reduced the probability of perceptually ambiguous or confusable productions. These results were obtained in the absence of explicit clarification requests, and persisted across words and over trials. Our findings suggest that speakers adapt their pronunciations based on the perceived communicative success of their previous productions in the current environment. We discuss why speakers make adaptive changes to their speech and what mechanisms might underlie speakers' ability to do so.

Dimensions of similarity in the mental lexicon

During language production planning, multiple candidate representations are implicitly activated prior to articulation. Lexical representations that are phonologically related to the target (phonological neighbors) are known to influence phonetic properties of the target word. However, the question of which dimensions of phonological similarity contribute to such lexical-phonetic effects remains unanswered. In the present study, we reanalyze phonetic data from a previous study, examining the contrasting predictions of different definitions of phonological similarity. Our results suggest that similarity at the level of position-specific phonological segments best predicts the influence of neighbor activation on phonetic properties of initial consonants.

The (in)dependence of articulation and lexical planning during isolated word production

The number of phonological neighbors to a word (PND) can affect its lexical planning and pronunciation. Similar parallel effects on planning and articulation have been observed for other lexical variables, such as a word's contextual predictability. Such parallelism is frequently taken to indicate that effects on articulation are mediated by effects on the time course of lexical planning. We test this mediation assumption for PND and find it unsupported. In a picture naming experiment, we measure speech onset latencies (planning), word durations, and vowel dispersion (articulation). We find that PND predicts both latencies and durations. Further, latencies predict durations. However, the effects of PND and latency on duration are independent: parallel effects do not imply mediation. We discuss the consequences for accounts of lexical planning, articulation, and the link between them. In particular, our results suggest that ease of planning does not explain effects of PND on articulation.