Intonational Phrase Boundaries Research Articles

Prosodic boundary cues in German: Evidence from the production and perception of bracketed lists

This study investigates prosodic phrasing of bracketed lists in German. We analyze variation in pauses, phrase-final lengthening and f0 in speech production and how these cues affect boundary perception. In line with the literature, it was found that pauses are often used to signal intonation phrase boundaries, while final lengthening and f0 are employed across different levels of the prosodic hierarchy. Deviations from expectations based on the standard syntax-prosody mapping are interpreted in terms of task-specific effects. That is, we argue that speakers add/delete prosodic boundaries to enhance the phonological contrast between different bracketings in the experimental task. In perception, three experiments were run, in which we tested only single cues (but temporally distributed at different locations of the sentences). Results from identification tasks and reaction time measurements indicate that pauses lead to a more abrupt shift in listeners׳ prosodic judgments, while f0 and final lengthening are exploited in a more gradient manner. Hence, pauses, final lengthening and f0 have an impact on boundary perception, though listeners show different sensitivity to the three acoustic cues.

Prosodic Marking of Narrow Focus in Seoul Korean

This paper explores prosodic marking of narrow (corrective) focus in Seoul Korean. Korean lacks lexical stress and it has a phonologized association between the Accentual Phrase (AP) initial segment and intonation. In the experiment, 4 speakers read sentences including a two-item list which were designed to elicit either an L or H AP-initial tone. The durational variations, the pitch events at prosodic boundaries, and F 0 span in 32 sentences read neutrally and 64 sentences read with one of the items under focus were analyzed. The results show that the focused constituent consistently initiates a new prosodic phrase. In comparison to the neutrally spoken or defocused counterpart, the focused constituent was more likely to be realized as an Intonational Phrase (IP) in some contexts. Bitonal IP boundary tones were more likely to occur under focus than monotonal tones. In addition, in focused constituents, durational expansion particularly at the phrase-edges, expansion in F 0 span, and raising of the phrase-initial pitch were observed. On the other hand, defocused constituents were not phonetically reduced compared to the neutral counterparts. The results imply that the phonetic cues spreading over the focused constituent complement the exaggerated prosodic boundaries.

Distribution of accentual phrase medial tones in Seoul Korean

According to the model of Korean (Seoul) intonation (Jun 1993, 2007), the underlying tonal pattern of an Accentual Phrase (AP) is either HHLH (if the AP-initial segment is aspirated or tense) or LHLH (elsewhere). The second tone, H (= + H in K-ToBI; Jun 2000), or the third tone, L (= L + in K-ToBI), or both are known to be often undershot when the AP is shorter than 4 syllables, but so far factors determining the distribution of these medial tones have not been investigated. This study aims to find predictors of AP-medial tone realization based on K-ToBI labeled speech of various speech styles. Preliminary results show that in general L + is more frequently undershot than + H regardless of the AP size. This pattern was clearer in L-initial APs than H-initial APs. Furthermore, the type of the AP-medial tone (when IP-final) showed an interaction with the type of immediately following Intonational Phrase boundary tones: L + was more often undershot than + H before L%, but the opposite was true before H(L)%. The results suggest that the tonal context adjacent to the AP-medial tone plays an important role in the distribution of AP-medial tones. More predictors will be discussed at the meeting.

ERP responses to processing prosodic phrasing of sentences in amplitude modulated noise

Intonation phrase boundaries (IPBs) were hypothesized to be especially difficult to process in the presence of an amplitude modulated noise masker because of a potential rhythmic competition. In an event-related potential study, IPBs were presented in silence, stationary, and amplitude modulated noise. We elicited centro-parietal Closure Positive Shifts (CPS) in 23 young adults with normal hearing at IPBs in all acoustic conditions, albeit with some differences. CPS peak amplitudes were highest in stationary noise, followed by modulated noise, and lowest in silence. Both noise types elicited CPS delays, slightly more so in stationary compared to amplitude modulated noise. These data suggest that amplitude modulation is not tantamount to a rhythmic competitor for prosodic phrasing but rather supports an assumed speech perception benefit due to local release from masking. The duration of CPS time windows was, however, not only longer in noise compared to silence, but also longer for amplitude modulated compared to stationary noise. This is interpreted as support for additional processing load associated with amplitude modulation for the CPS component. Taken together, processing prosodic phrasing of sentences in amplitude modulated noise seems to involve the same issues that have been observed for the perception and processing of segmental information that are related to lexical items presented in noise: a benefit from local release from masking, even for prosodic cues, and a detrimental additional processing load that is associated with either stream segregation or signal reconstruction.

How does prosody influence speech categorization?

A recent study (Kim & Cho, 2013, The Journal of the Acoustical Society of America) reported that the perception of a prosodic boundary leads to a shift in a stop-identification function in English, so that stops with a relatively long VOT are accepted as voiced if occurring after a major prosodic boundary. Even Korean learners of English showed such a shift. This shift would seem to result from compensation for post-boundary lengthening effects (or domain-initial strengthening) and thereby help to overcome the invariance problem in speech perception. In two experiments, we ask how this effect comes about. The first experiment tested whether a simple adjustment to a change in overall speaking rate would be sufficient to account for the shift. Results showed that while the global speaking-rate change modulates phonetic categorization in a similar way as a change in the prosodic boundary strength, the speaking-rate effect is not sufficient to explain the boundary effect. That is, there was a more robust shift in a stop identification function with localized slowing down of the final syllable due to an intonational phrase (IP) boundary than with global slowing down of speaking rate. The second experiment therefore investigated the contribution of an F0 cue to the observed perceptual shift and found that the presence or absence of the F0 cue did not mediate the effect of prosodic boundaries on phonetic categorization. This suggests that a perception shift in phonetic categorization stems primarily from the listeners’ adjustment to temporal variation, though its source is different from the speaking rate. The results are considered in terms of two possible accounts: one that takes both the boundary-induced and the speaking rate-induced effects as listeners’ adjustments to low-level temporal variation, and the other that separates them by taking the boundary-induced effects to arise with computation of higher-level prosodic structure, given that the source of the localized slowing down effect is a prosodic boundary.

Listeners use intonational phrase boundaries to project turn ends in spoken interaction

In conversation, turn transitions between speakers often occur smoothly, usually within a time window of a few hundred milliseconds. It has been argued, on the basis of a button-press experiment [De Ruiter, J. P., Mitterer, H., & Enfield, N. J. (2006). Projecting the end of a speaker's turn: A cognitive cornerstone of conversation. Language, 82(3):515–535], that participants in conversation rely mainly on lexico-syntactic information when timing and producing their turns, and that they do not need to make use of intonational cues to achieve smooth transitions and avoid overlaps. In contrast to this view, but in line with previous observational studies, our results from a dialogue task and a button-press task involving questions and answers indicate that the identification of the end of intonational phrases is necessary for smooth turn-taking. In both tasks, participants never responded to questions (i.e., gave an answer or pressed a button to indicate a turn end) at turn-internal points of syntactic completion in the absence of an intonational phrase boundary. Moreover, in the button-press task, they often pressed the button at the same point of syntactic completion when the final word of an intonational phrase was cross-spliced at that location. Furthermore, truncated stimuli ending in a syntactic completion point but lacking an intonational phrase boundary led to significantly delayed button presses. In light of these results, we argue that earlier claims that intonation is not necessary for correct turn-end projection are misguided, and that research on turn-taking should continue to consider intonation as a source of turn-end cues along with other linguistic and communicative phenomena.

Relações entre pausas e constituintes prosódicos na fala de crianças com desenvolvimento típico de linguagem

Objetivo (1) Verificar a distribuição de pausas não hesitativas e hesitativas em entrevistas com crianças em desenvolvimento típico de linguagem; (2) verificar, nas pausas não hesitativas, sua relação com limites de enunciados fonológicos e de frases entonacionais; (3) verificar, nas pausas hesitativas, sua distribuição entre início e interior de enunciados. Métodos As pausas foram extraídas de amostras de fala de quatro crianças com desenvolvimento típico de linguagem e idades entre quatro e cinco anos que, em 2011, frequentavam o nível Infantil II de uma Escola Municipal de Educação Infantil de Marília. As amostras de fala versavam sobre temas trabalhados em dez propostas pedagógicas desenvolvidas na sala de aula das crianças. Posteriormente, foi realizada, pela pesquisadora, uma inspeção de outiva (complementada pelo julgamento perceptual-auditivo de um grupo de cinco juízes) de cada um dos arquivos, a fim de se identificar os pontos de pausas. Resultados Não foi verificada diferença estatística na distribuição entre pausas hesitativas e não hesitativas; foi verificada tendência marginal de maior ocorrência de pausas em limites de frases entonacionais, do que em limites de enunciados fonológicos; não houve diferença estatística na distribuição entre pausas hesitativas em início e em interior de enunciados. Conclusão A instabilidade na distribuição das pausas é um importante recurso linguístico de observação dos domínios prosódicos que se mostram como mais, ou menos, dominados pelas crianças na aquisição da linguagem.

How listeners weight acoustic cues to intonational phrase boundaries.

The presence of an intonational phrase boundary is often marked by three major acoustic cues: pause, final lengthening, and pitch reset. The present study investigates how these three acoustic cues are weighted in the perception of intonational phrase boundaries in two experiments. Sentences that contained two intonational phrases with a critical boundary between them were used as the experimental stimuli. The roles of the three acoustic cues at the critical boundary were manipulated in five conditions. The first condition featured none of the acoustic cues. The following three conditions featured only one cue each: pause, final lengthening, and pitch reset, respectively. The fifth condition featured both pause duration and pre-final lengthening. A baseline condition was also included in which all three acoustic cues were preserved intact. Listeners were asked to detect the presence of the critical boundaries in Experiment 1 and judge the strength of the critical boundaries in Experiment 2. The results of both experiments showed that listeners used all three acoustic cues in the perception of prosodic boundaries. More importantly, these acoustic cues were weighted differently across the two experiments: Pause was a more powerful perceptual cue than both final lengthening and pitch reset, with the latter two cues perceptually equivalent; the effect of pause and the effects of the other two acoustic cues were not additive. These results suggest that the weighting of acoustic cues contributes significantly to the perceptual differences of intonational phrase boundary.

Can intonational phrase structure be primed (like syntactic structure)?

In 3 experiments, we investigated whether intonational phrase structure can be primed. In all experiments, participants listened to sentences in which the presence and location of intonational phrase boundaries were manipulated such that the recording included either no intonational phrase boundaries, a boundary in a structurally dispreferred location, a boundary in a preferred location, or boundaries in both locations. In Experiment 1, participants repeated the sentences to test whether they would reproduce the prosodic structure they had just heard. Experiments 2 and 3 used a prime-target paradigm to evaluate whether the intonational phrase structure heard in the prime sentence might influence that of a novel target sentence. Experiment 1 showed that participants did repeat back sentences that they had just heard with the original intonational phrase structure, yet Experiments 2 and 3 found that exposure to intonational phrase boundaries on prime trials did not influence how a novel target sentence was prosodically phrased. These results suggest that speakers may retain the intonational phrasing of a sentence, but this effect is not long-lived and does not generalize across unrelated sentences. Furthermore, these findings provide no evidence that intonational phrase structure is formulated during a planning stage that is separate from other sources of linguistic information.

Learning Phonemic Vowel Length from Naturalistic Recordings of Japanese Infant-Directed Speech

In Japanese, vowel duration can distinguish the meaning of words. In order for infants to learn this phonemic contrast using simple distributional analyses, there should be reliable differences in the duration of short and long vowels, and the frequency distribution of vowels must make these differences salient enough in the input. In this study, we evaluate these requirements of phonemic learning by analyzing the duration of vowels from over 11 hours of Japanese infant-directed speech. We found that long vowels are substantially longer than short vowels in the input directed to infants, for each of the five oral vowels. However, we also found that learning phonemic length from the overall distribution of vowel duration is not going to be easy for a simple distributional learner, because of the large base-rate effect (i.e., 94% of vowels are short), and because of the many factors that influence vowel duration (e.g., intonational phrase boundaries, word boundaries, and vowel height). Therefore, a successful learner would need to take into account additional factors such as prosodic and lexical cues in order to discover that duration can contrast the meaning of words in Japanese. These findings highlight the importance of taking into account the naturalistic distributions of lexicons and acoustic cues when modeling early phonemic learning.

The role of pause as a prosodic boundary marker: Language ERP studies in German 3- and 6-year-olds

Spoken language is hierarchically structured into prosodic units divided by prosodic breaks. The largest prosodic breaks in an utterance are intonational phrase boundaries (IPBs), which are defined by three acoustic cues, namely, pitch change, preboundary lengthening, and pausing. Previous studies have revealed that the electrophysiological marker of IPB perception, the Closure Positive Shift (CPS), is established between 2 and 3 years of age. Here, we examined the neural activity underlying IPB perception in children by targeting their reliance on pausing; hypothesized to be a key boundary cue in German. To evaluate the role of pausing, we tested IPB perception without the boundary pause, but with pitch change and preboundary lengthening. We tested children at the age of 3 years, when the CPS in response to IPBs has just emerged, and at 6 years, when language abilities are further developed. Results revealed that 6-year-olds, but not 3-year-olds, show the CPS in response to IPBs without full prosodic marking. These results indicate developmental differences with respect to the role of pausing as a prosodic boundary cue in German. The correlation of children's IPB perception and their syntactic abilities further corroborates the close prosody–syntax interaction in children's advancing ability to process phrase structure.

Notes de recheche sur l'accentuation et le phrasé prosodique à la lumière des corpus de français

In this paper the main rules for stress assignment in French, the constraints relative to the formation of minor prosodic units (Accentual Phrases) and major prosodic units (Intonational Phrases, IP) are first recalled. A procedure developed in order to annotate semi-automatically these phenomena in different French corpora is then described. Finally the results of two studies are presented. The first one is conducted on a 4-hour long corpus (designed for the statistical study of regional variation in Swiss French). It aims at testing the robustness of two phonological rules implicated in the formation of Accentual Phrase in French (deaccentuation of pre-nominal adjectives (a sequel to the Align-XHead constraint), accentual clash avoidance rule). The second summarizes the main results obtained in the author’s PhD thesis (Avanzi, 2012). It is conducted on a set of data containing approximately 800 dislocated-sentences. It questions the weight of syntactic and information structure cues in front of prosodic structure cues in order to identify Intonational Phrase boundaries.

Do contrastive accents modulate the effect of intonational phrase boundaries in parsing?

Two experiments examined the effect of intonational phrase boundaries (Experiment 1) and interactions between intonational phrase boundaries and contrastive accents (Experiment 2) in parsing, using a sentence continuation judgment task. Across experiments, we found that intonational phrase boundaries were consistently interpreted as signaling syntactic structure as long as there were no alternative reasons for them to be present. Experiment 2 showed that different prosodic cues interact in syntactic processing. The effect of intonational phrase boundaries was modulated by contrastive accents through weaker intermediate phrase boundaries that followed contrastive accents, suggesting that the effects of pitch accents are indirect in syntactic processing.

Morphological alternations at the intonational phrase edge

This article develops an analysis of a pair of morphological alternations in K’ichee’ (Mayan) that are conditioned at the right edge of intonational phrase boundaries. I propose a syntax-prosody mapping algorithm that derives intonational phrase boundaries from the surface syntax, and then argue that each alternation can be understood in terms of output optimization (Mascaro 2007; Mester 1994). The important fact is that K’ichee’ requires a prominence peak rightmost in the intonational phrase, and so the morphological alternations occur in order to ensure an optimal host for this prominence peak. Finally, I consider the wider implications of the analysis for the architecture of the syntax-phonology interface, especially as it concerns late-insertion theories of morphology (Anderson 1982, 1992; Embick and Noyer 2001; Halle and Marantz 1993; Hayes 1990, among others). The primary result is that late lexical insertion must occur at least as late as the construction of intonational phrases.

Prosodic boundary strength: An articulatory and perceptual study

This study examines the production and perception of Intonational Phrase (IP) boundaries. In particular, it investigates (1) whether the articulatory events that occur at IP boundaries can exhibit temporal distinctions that would indicate a difference in degree of disjuncture, and (2) to what extent listeners are sensitive to the effects of such differences among IP boundaries. Two experiments investigate these questions. An articulatory kinematic experiment examines the effects of structural differences between IP boundaries on the production of those boundaries. In a perception experiment listeners then evaluate the strength of the junctures occurring in the utterances produced in the production study. The results of the studies provide support for the existence of prosodic strength differences among IP boundaries and also demonstrate a close link between the production and perception of prosodic boundaries. The results are discussed in the context of possible linguistic structural explanations, with implications for cognitive accounts for the creation, implementation, and processing of prosody.

Automatic prosodic event detection using a novel labeling and selection method in co-training

Most previous approaches to automatic prosodic event detection are based on supervised learning, relying on the availability of a corpus that is annotated with the prosodic labels of interest in order to train the classification models. However, creating such resources is an expensive and time-consuming task. In this paper, we exploit semi-supervised learning with the co-training algorithm for automatic detection of coarse-level representation of prosodic events such as pitch accent, intonational phrase boundaries, and break indices. Since co-training works on the condition that the views are compatible and uncorrelated, and real data often do not satisfy these conditions, we propose a method to label and select examples in co-training. In our experiments on the Boston University radio news corpus, when using only a small amount of the labeled data as the initial training set, our proposed labeling method can effectively use unlabeled data to improve performance and finally reach performance close to the results of the supervised method using more labeled data. We perform a thorough analysis of various factors impacting the learning curves, including labeling error rate and informativeness of added examples, performance of the individual classifiers and their difference, and the initial and added data size.

Perceptual Recovery from Consonant-Cluster Simplification in Korean Using Language-Specific Phonological Knowledge

Two experiments examined whether perceptual recovery from Korean consonant-cluster simplification is based on language-specific phonological knowledge. In tri-consonantal C1C2C3 sequences such as /lkt/ and /lpt/ in Seoul Korean, either C1 or C2 can be completely deleted. Seoul Koreans monitored for C2 targets (/p/ or / k/, deleted or preserved) in the second word of a two-word phrase with an underlying /l/-C2-/t/ sequence. In Experiment 1 the target-bearing words had contextual lexical-semantic support. Listeners recovered deleted targets as fast and as accurately as preserved targets with both Word and Intonational Phrase (IP) boundaries between the two words. In Experiment 2, contexts were low-pass filtered. Listeners were still able to recover deleted targets as well as preserved targets in IP-boundary contexts, but better with physically-present targets than with deleted targets in Word-boundary contexts. This suggests that the benefit of having target acoustic-phonetic information emerges only when higher-order (contextual and phrase-boundary) information is not available. The strikingly efficient recovery of deleted phonemes with neither acoustic-phonetic cues nor contextual support demonstrates that language-specific phonological knowledge, rather than language-universal perceptual processes which rely on fine-grained phonetic details, is employed when the listener perceives the results of a continuous-speech process in which reduction is phonetically complete.

Prosodic characteristics of speech directed to adults and to infants with and without hearing loss.

Studies have shown that infant‐direct speech (IDS) is distinguished from adult‐directed speech (ADS) via a variety of acoustic‐prosodic characteristics, including fundamental frequency and rate. However, little is known about how IDS and ADS may be distinguished in terms of linguistically relevant prosodic constructs, such as pitch accents, nor how these constructs map onto acoustic differences previously identified for IDS vs ADS. To investigate these issues, longitudinal recordings of mothers reading a storybook to their typically developing infants and to an experimenter were made when the infants were approximately 3, 6, or 9 months old. Trained analysts used an annotation system to code prosodic characteristics, including rhythmic prominences, pitch accents, and intonation phrase boundaries. Preliminary analyzes of labeled corpora revealed that mothers produced significantly more prominences in IDS than in ADS. In addition, mothers showed substantial individual differences in rates of prominence production in IDS and ADS. Future work will include acoustic analyzes of labeled prosodic constructs, as well as investigations of how prosodic variation in mothers’ speech may predict speech‐language outcomes in both normal‐hearing children as well as children with hearing loss. [Work supported by NIH‐NIDCD Grant No. R01DC008581.]

The Cognitive Processing of Prosodic Boundary and Its Related Brain Effect in Quatrain

Prosodic boundary, as an integral part of prosodic features in spoken language, is very important in sentence and discourse comprehension. Recently, researchers have shown increasing interest in the neural mechanism of prosodic boundary processing. Numerous studies have found that CPS, a special ERP component reflecting the closure of phonological phrase, could be induced by phonological phrase boundary embedded in a sentence. Also, researches have demonstrated that intonational phrase boundary in the end of a sentence consistently elicited P3, which reflects the operation of "syntactic closure" as well as the completeness of language unit. The present study aims to investigate the cognitive processing of intonational phrase boundary embedded in discourse and its related brain effect using ERP. To explore the processing of intonational phrase boundary in discourse, quatrain was used, which is composed of four sentences and five or seven characters in each sentence. Twenty (10 males) healthy undergraduates participated in the experiment. The participants were told to listen carefully to each poem, and complete a word discrimination task. Specifically, if the word "Space" was presented, they were asked to press the spacebar to continue. If other words were presented, they were required to press the "F" or "J" key to indicate whether the word appeared in the poem they had just heard. The EEG was recorded from 64 scalp channels using electrodes mounted in an elastic cap. Boundary-related ERPs were calculated for a 1500 ms epoch including a 200 ms pre-boundary syllable baseline. It was found that the three intonational phrase boundaries embedded in the quatrain elicited CPS respectively, with no differences in time course, amplitude and scalp distribution, indicating that prosodic boundary processing was not influenced by its position in discourse. Moreover, the final sentence of both five-character-quatrain and seven-character-quatrain evoked the P3 effect, with the amplitude elicited by the former one lower than that of the later one, but no differences in scalp distribution and onset latency. The present study suggests that boundaries conveying both the closure of preceding information and the prediction of upcoming information will induce CPS, while boundaries reflecting only the closure of preceding information will elicit P3. The nature and characteristics of these two components were also discussed in the present study.

Perception of Chinese poem and its electrophysiological effects

A neural correlate for phrase boundary perception in language has recently been identified as a reliable and replicable brain effect. It is called the closure positive shift (CPS) and has an equivalent in the perception of music (music CPS). Nevertheless, either in language or in music, this component is elicited by phrase boundary embedded in sentence or melody. Poetry, as the interlude of language and music, is a special kind of discourse and promising material to explore prosodic boundary processing beyond sentence level. The aim of the present study was to investigate the cognitive processing of hierarchical prosodic boundaries in Chinese Tang poem using rhythm matching task. There are generally four hierarchical levels in each poem, including foot boundary, phonological phrase boundary, intonational phrase boundary, and couplet boundary. The electrophysiological results indicated that all the prosodic boundaries of different levels in poems could give rise to the CPS reflecting prosodic phrasing. Furthermore, as the prosodic hierarchical level became higher, the onset latency of the CPS got longer, suggesting the influence of retrospective processing of former information. With regard to the amplitude, we analyzed the CPS amplitude in every 100 ms time window. It was showed that phonological phrase boundary elicited higher CPS amplitude as compared to that evoked by couplet boundary in an earlier time window, whereas in a later time window both of them were lower than the CPS correlated to intonational phrase boundary. The present results further shape our understanding of the CPS component and its relation to the processes involved in prosodic phrasing.