Perception Of Prosodic Boundaries Research Articles

Age effects on prosodic boundary perception.

The redundancy hypothesis proposes that older listeners need a larger array of acoustic cues than younger listeners for effective speech perception. This research investigated this hypothesis by examining the aging effects on the use of prosodic cues in speech segmentation in Mandarin Chinese. We examined how younger and older listeners perceived prosodic boundaries using three main prosodic cues (pause, final lengthening, and pitch change) across eight conditions involving different cue combinations. The stimuli consisted of syntactically ambiguous phrase pairs, each containing two or three objects. Participants (22 younger listeners and 22 older listeners) performed a speech recognition task to judge the number of objects they heard. Both groups primarily relied on the pause cue for identifying prosodic boundaries, using final lengthening and pitch change as secondary cues. However, older listeners showed reduced sensitivity to these cues, compensating by integrating the primary cue pause with the secondary cue pitch change for more precise segmentation. The present study reveals older listeners' integration strategy in using prosodic cues for speech segmentation, supporting the redundancy hypothesis. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Increased Pre-Boundary Lengthening Does Not Enhance Implicit Intonational Phrase Perception in European Portuguese: An EEG Study.

Prosodic phrasing is the segmentation of utterances into prosodic words, phonological phrases (smaller units) and intonational phrases (larger units) based on acoustic cues-pauses, pitch changes and pre-boundary lengthening. The perception of prosodic boundaries is characterized by a positive event-related potential (ERP) component, temporally aligned with phrase boundaries-the Closure Positive Shift (CPS). The role of pre-boundary lengthening in boundary perception is still a matter of debate: while studies on phonological phrase boundaries indicate that all three cues contribute equally, approaches to intonational phrase boundaries highlight the pause as the most powerful cue. Moreover, all studies used explicit boundary recognition tasks, and it is unknown how pre-boundary lengthening works in implicit prosodic processing tasks, characteristic of real-life contexts. In this study, we examined the effects of pre-boundary lengthening (original, short, and long) on the EEG responses to intonational phrase boundaries (CPS effect) in European Portuguese, using an implicit task. Both original and short versions showed equivalent CPS effects, while the long set did not elicit the effect. This suggests that pre-boundary lengthening does not contribute to improved perception of boundaries in intonational phrases (longer units), possibly due to memory and attention-related constraints.

The effect of different information sources on prosodic boundary perception.

This study aims to quantify the effect of several information sources: acoustic, higher-level linguistic, and knowledge of the prosodic system of the language, on the perception of prosodic boundaries. An experiment with native and non-native participants investigating the identification of prosodic boundaries in Japanese was conducted. It revealed that non-native speakers as well as native speakers with access only to acoustic information can recognize boundaries better than chance level. However, knowledge of both the prosodic system and of higher-level information are required for a good boundary identification, each one having similar or higher importance than that of acoustic information.

Prosody-syntax interface and prosodic phrasing in brazilian portuguese

This paper focuses on the Brazilian Portuguese (PB) prosodic phrasing and has two main goals: (1) to find a correlation between the prosodic constituents boundaries, as described by the Prosodic Hierarchy Theory (Nespor & Vogel, 2007 [1986], a.o.) and the perception and production of spontaneous and reading speech breaks, and (2) to describe the phonological characteristics and the syntactic ranking of perceived and non perceived edges. The corpus under analysis includes 5 extracts both of spontaneous and reading speech lasting about 2 minutes each. The reading speech (LE) emerged from the spontaneous speech (FE) orthographic transcription which was collected from an interview in an informal environment. In the perception test, 11 referees heard the 10 speaking extracts, without punctuation, and marked the perceived breaks in the orthographic transcription of each of them. Both the 5 speakers and the 11 referees were students at UFRJ, born in Rio de Janeiro, and were between 22 and 38 years old.The results point out that the prosodic breaks are mainly perceived at the intonational phrase (I) boundary, regardless of the speech style (FE: 91%; LE 99%). However, in LE, 64% of the foreseen I boundaries, described by the Prosodic Hierarchy Theory, were perceived as breaks, but in FE, just 37% were perceived. The most usual nuclear contour in both styles is H+L* L% (this being the Portuguese neutral declarative contour), but its occurrence frequency at perceived breaks draws a distinction between LE and FE (67% and 30%, respectively). In FE, contours like L+H* H% and L*+H H% are also produced (34%). In general, descendant nuclei in LE are predominant, as well as the edge tone L; in FE, both the descendant and ascendant nuclei distribution and low or high boundaries are similar. After running a statistic test, the appearance of an L edge, as a predictive for perception, was globally significant. Concerning the syntactic boundary, it was statistically checked and the result points out that breaks are mainly perceived at the matrix phrase limit (LE: 59%; FE: 61%,), showing the endurance of the matrix phrase edge/I boundary mapping. In general, FE has proved to have a bigger variation on the relation of predicted, perceived and produced, as it was expected, which was also confirmed by statistics. Therefore, the results show that the foreseen I phrasing is fairly robust in both styles, once only 13% of the predicted I boundaries have not been produced as so, regarding intonation. Besides, just 1,4% of the predicted phonological phrase (f) boundaries (and produced as Is) were perceived as breaks by the referees. With this study one may conclude that LE and FE share the same prosodic grammar, performed by the same type of phonological/syntactic cues; nevertheless, these are more consistent in LE and have a more disperse way in FE, adding to a greater difficulty at the systematic perception of prosodic boundaries in FE than in LE.

Individual differences in the production and perception of prosodic boundaries in American English

The goal of the current study is to investigate whether the acoustic properties that speakers use to encode prosodic contrasts in their production of Intonational Phrase (IP) boundaries are closely related to the properties they used to perceive those contrasts. The focus is on pause, phrase-final lengthening, and pitch reset. Thirty-two participants read sentence pairs differing in the type of boundary—word versus IP boundary. Results show that participants differed in both the combination of the acoustic properties used and the degree to which they used them to mark IP boundaries. For the perception study, the same stimuli were recorded by a model talker and the three acoustic characteristics were manipulated to systematically vary the presence and degree of the IP boundary cues in the auditory stimuli. Twenty participants from the production study participated in an eye-tracking experiment. Results of the Generalized Additive Mixed Model analyses showed limited evidence that the perception of IP boundaries was influenced by how the participants modulated the acoustic properties in production. [Work supported by NSF.]

Modelling automatic detection of prosodic boundaries for brazilian portuguese spontaneous speech

Speech is segmented into intonational units marked by prosodic boundaries. This segmentation is claimed to have important consequences on syntax, information structure and cognition. This work aims both to investigate the phonetic-acoustic parameters that guide the production and perception of prosodic boundaries, and to develop models for automatic detection of prosodic boundaries in male monological spontaneous speech of Brazilian Portuguese. Two samples were segmented into intonational units by two groups of trained annotators. The boundaries perceived by the annotators were tagged as either terminal or non-terminal. A script was used to extract 111 phonetic-acoustic parameters along speech signal in a right and left windows around the boundary of each phonological word. The extracted parameters comprise measures of (1) Speech rate and rhythm; (2) Standardized segment duration; (3) Fundamental frequency; (4) Intensity; (5) Silent pause. The script considers as prosodic boundary positions at which at least 50% of the annotators indicated a boundary of the same type. A training of models composed by the parameters extracted by the script was developed; these models, were then improved heuristically. The models were developed from the two samples and from the whole data, both using non-balanced and balanced data. Linear Discriminant Analysis algorithm was adopted to produce the models. The models for terminal boundaries show a much higher performance than those for non-terminal ones. In this paper we: (i) show the methodological procedures; (ii) analyze the different models; (iii) discuss some strategies that could lead to an improvement of our results.

Detecção automática de fronteiras prosódicas entre unidades entonacionais

A fala é segmentada em unidades entonacionais marcadas por fronteiras prosódicas. Este trabalho tem como objetivo investigar os parâmetros fonético-acústicos que orientam a produção e a percepção de fronteiras prosódicas e desenvolver modelos para detecção automática de fronteiras prosódicas em fala espontânea. Duas amostras de trechos de fala espontânea masculina foram segmentadas em unidades entonacionais por dois grupos de segmentadores treinados. As fronteiras percebidas pelos segmentadores foram anotadas como terminais (TB) ou não-terminais (NTB). Um script foi utilizado para extrair parâmetros fonético-acústicos ao longo do sinal de fala. Os parâmetros extraídos compreendem medidas de: 1) Velocidade e ritmo da fala; 2) Duração normalizada; 3) Frequência fundamental; 4) Intensidade; 5) Pausa silenciosa. Foi desenvolvido um treinamento de modelos compostos por múltiplos parâmetros projetados para a identificação automática das fronteiras marcadas pelos segmentadores. Utilizou-se o algoritmo Linear Discriminant Analysis e considerou-se como fronteira posições em que pelo menos 50% dos segmentadores indicaram uma fronteira do mesmo tipo. O modelo de detecção automática de fronteiras terminais mostra uma convergência de 80% em relação às fronteiras terminais observadas pelos segmentadores na amostra I. Para fronteiras não-terminais, foram obtidos três modelos de classificação estatística. Juntos, os três modelos mostram uma convergência de 98% em relação às fronteiras não-terminais observadas pelos segmentadores na amostra I. Os modelos foram validados posteriormente na amostra II. Os resultados da validação indicam que o desempenho do modelo TB é de 74% e o dos modelos NTB é de 88% na amostra II.

Language-specific prosodic acquisition: A comparison of phrase boundary perception by French- and German-learning infants

This study compares the development of prosodic processing in French- and German-learning infants. The emergence of language-specific perception of phrase boundaries was directly tested using the same stimuli across these two languages. French-learning (Experiment 1, 2) and German-learning 6- and 8-month-olds (Experiment 3) listened to the same French noun sequences with or without major prosodic boundaries ([Loulou et Manou][et Nina]; [Loulou et Manou et Nina], respectively). The boundaries were either naturally cued (Experiment 1), or cued exclusively by pitch and duration (Experiment 2, 3). French-learning 6- and 8-month-olds both perceived the natural boundary, but neither perceived the boundary when only two cues were present. In contrast, German-learning infants develop from not perceiving the two-cue boundary at 6 months to perceiving it at 8 months, just like German-learning 8-month-olds listening to German (Wellmann, Holzgrefe, Truckenbrodt, Wartenburger, & Höhle, 2012). In a control experiment (Experiment 4), we found little difference between German and French adult listeners, suggesting that later, French listeners catch up with German listeners. Taken together, these cross-linguistic differences in the perception of identical stimuli provide direct evidence for language-specific development of prosodic boundary perception.

Phonemes, words, and phrases: Tracking phonological processing in pre-schoolers developing dyslexia

ObjectivesIndividuals with dyslexia often suffer from deficient segmental phonology, but the status of suprasegmental phonology (prosody) is still discussed. MethodsIn three passive-listening event-related brain potential (ERP) studies, we examined prosodic processing in literacy-impaired children for various prosodic units by contrasting the processing of word-level and phrase-level prosody, alongside segmental phonology. We retrospectively analysed school children’s ERPs at preschool age for discrimination of vowel length (phoneme processing), discrimination of stress pattern (word-level prosody), and processing of prosodic boundaries (phrase-level prosody). ResultsWe found differences between pre-schoolers with and without later literacy difficulties for phoneme and stress pattern discrimination, but not for prosodic boundary perception. ConclusionOur findings complement the picture of phonological processing in dyslexia by confirming difficulties in segmental phonology and showing that prosodic processing is affected for the smaller word level, but not the larger phrase level. SignificanceThese findings might have implications for early interventions, considering both phonemic awareness and stress pattern training.

Infants' Processing of Prosodic Cues: Electrophysiological Evidence for Boundary Perception beyond Pause Detection.

Infants as young as six months are sensitive to prosodic phrase boundaries marked by three acoustic cues: pitch change, final lengthening, and pause. Behavioral studies suggest that a language-specific weighting of these cues develops during the first year of life; recent work on German revealed that eight-month-olds, unlike six-month-olds, are capable of perceiving a prosodic boundary on the basis of pitch change and final lengthening only. The present study uses Event-Related Potentials (ERPs) to investigate the neuro-cognitive development of prosodic cue perception in German-learning infants. In adults' ERPs, prosodic boundary perception is clearly reflected by the so-called Closure Positive Shift (CPS). To date, there is mixed evidence on whether an infant CPS exists that signals early prosodic cue perception, or whether the CPS emerges only later-the latter implying that infantile brain responses to prosodic boundaries reflect acoustic, low-level pause detection. We presented six- and eight-month-olds with stimuli containing either no boundary cues, only a pitch cue, or a combination of both pitch change and final lengthening. For both age groups, responses to the former two conditions did not differ, while brain responses to prosodic boundaries cued by pitch change and final lengthening showed a positivity that we interpret as a CPS-like infant ERP component. This hints at an early sensitivity to prosodic boundaries that cannot exclusively be based on pause detection. Instead, infants' brain responses indicate an early ability to exploit subtle, relational prosodic cues in speech perception-presumably even earlier than could be concluded from previous behavioral results.

Neural correlates of prosodic boundary perception in German preschoolers: If pause is present, pitch can go

Children׳s perception of prosodic phrasing provides a head start into the discovery of speech structure. Based on the close prosody–syntax correspondence, children can infer the underlying syntactic structure from the acoustic modulations of prosodic boundaries, typically consisting of co-occurring pitch changes, preboundary lengthening, and pausing. Previous electrophysiological studies revealed that listeners are to some degree flexible in the detection of major prosodic boundaries that are not marked with all three of the suprasegmental cues. Adults and 6-year-olds still showed the brain response for prosodic boundary perception, the Closure Positive Shift (CPS), when pauses marking boundaries were deleted. In contrast, younger children at 3 years did not show this ability yet, but required pausing to complement the other boundary cues. Following the hypothesis that German weights duration cues more heavily than pitch cues, we here examined 3-year-olds׳ brain responses to prosodic phrasing, testing the role of boundary-related pitch changes. Results revealed that children at this age even showed the CPS in response to pitch-neutralized boundaries with only pausing and preboundary lengthening being present. These results indicate differential roles of acoustic cues in boundary perception, with a preferential reliance on duration cues over pitch changes in 3-year-olds. This preference likely results from the characteristics of the German intonation system and furthers the discussion of cross-linguistic differences in the weighting of prosodic boundary cues.

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.

Gradient prosodic boundary perception and recursion in syntactic disambiguation

Most research examining prosodic structure has made the assumption that prosodic boundaries are categorical and discrete, and all instances of a specific category are linguistically equivalent (Snedeker and Casserly, 2010). The empirical evidence for this notion is the finding that certain within-category differences do not cause changes in attachment ambiguity (Carlson et al., 2001, experiment 2). However, several studies have shown that prosodic boundaries which arguably instantiate the same category are not only produced differently (Ladd, 1988, 2008; Krivokapić and Byrd, 2012), but listeners are also sensitive to variations in production within categories (Wagner and Crivellaro, 2010; Krivokapić and Byrd, 2012). Such findings suggest that, contrary to traditional assumptions, a certain degree of recursion may exist in prosodic structure. Our study further examines this controversial concept, as we test whether listeners are able to differentiate various meanings of coordinative structures using gradient strengths of a single boundary type while holding all other variables constant. If prosodic structure is non-recursive and phonetic gradiency within a certain boundary category is not linguistically meaningful listeners should not be able to perform this task. However, listeners in this study were able to successfully differentiate coordinative structures based on within-category boundary strength alone.

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.

The role of syntactic structure in guiding prosody perception with ordinary listeners and everyday speech

The relationship between syntactic and prosodic phrase structures is investigated in the production and perception of spontaneous speech. Three hypotheses are tested: (1) syntax influences prosody production; (2) listeners' perception of prosodic boundaries is sensitive to acoustic duration; and (3) syntax directly influences boundary perception, (partly) independent of the acoustic evidence for boundaries. Data are from the Buckeye corpus of conversational speech, and the real-time prosodic transcription of those data by 97 untrained listeners. Inter-transcriber agreement codes boundary strength at word junctures, and Boundary scores are shown to be correlated with both the syntactic context and vowel duration of a word. Vowel duration is also correlated with syntactic context, but the effect of syntactic context on boundary perception is not fully explained by vowel duration. Regression analyses show that syntactic clause boundaries and vowel duration are the first and second strongest predictors of boundary perception in spontaneous speech.

Perception of prosodic boundaries in spontaneous speech with and without silent pauses.

In speech comprehension, listeners attend to variation in multiple acoustic parameters encoding prosodic structure. Given the multiplicity of acoustic cues, we ask whether prosody perception is dependent on any individual cue or whether acoustic redundancy encoding prosody supports robust prosody perception in the absence of an individual cue. The present paper reports on a study of boundary perception in spontaneous speech with and without silent pause as a boundary cue. Prior studies show that in read speech, silent pause is important for boundary perception, while in spontaneous speech, listeners can detect boundaries without pauses. Our study tests the role of pause in boundary perception with two versions of 36 short speech excerpts from the Buckeye Corpus: one with pauses intact and another with all pauses truncated to 20 ms. In real-time transcription tasks based only on auditory impression, boundary locations were marked by 74 subjects for the intact stimuli and by an additional 15 subjects for truncated excerpts. Inter-transcriber agreement was comparable across the intact and truncated conditions. Paired-sample t-tests show significantly higher rates of boundary perception for intact stimuli indicating that silent pause is an important but not necessary cue to boundary perception and cue redundancy allows for robust perception.

Perception of prosodic hierarchical boundaries in Mandarin Chinese sentences

The current study aimed at investigating the processing of prosodic hierarchical boundaries in Mandarin Chinese sentences using electroencephalography, mainly focused on the following questions: (1) whether prosodic boundaries at different levels could evoke the closure positive shift reflecting prosodic boundary perception; (2) what were the differences between them at latency, amplitude and topography; (3) whether this positive component was modified by the variations of acoustic cues (e.g. pause). Main results were: (1) As the previous studies indicated, intonational phrases elicited the closure positive shift as a marker of online speech structuring; (2) phonological phrases evoked the same positive effect with shorter onset latency and somewhat lower amplitude; (3) when the pauses in the vicinity of prosodic boundaries were entirely removed, the original latency difference between the two conditions disappeared, which clearly demonstrated the influence of pause on prosodic boundary processing; (4) prosodic word boundaries only induced amplitude variation waving around the baseline, which was more positive compared with the one elicited by syllable boundaries. The present results indicated that listeners were very sensitive to both intonational phrase boundaries and phonological phrase boundaries.

Gradiency and categoricity in prosodic boundary production and perception

A study investigating whether the production and perception of prosodic boundaries is categorical or gradient is presented. Most theories assume a small set of prosodic categories which are marked by categorically different prosodic boundaries (e.g., Beckman & Pierrehumbert 1986 Phonology Yearbook, 3, 255–309, Nespor & Vogel 1986 Prosodic Phonology), while an alternative view suggests the possibility of gradiently varying prosodic boundaries (e.g., Byrd & Saltzman, 2003 J. of Phonetics, 31, 149–180). The first part of this study is an articulatory study investigating the production of twenty-four prosodic junctures ranging from no boundary to very strong boundary. In the second part of the study listeners evaluate the perception of these same boundaries. Two evaluations (histograms and fitting mixture distributions) were conducted on both the production and on the perception data. The production of prosodic boundaries was found to be categorical, showing a large (IP) and a predominantly small prosodic boundary. The perception of prosodic boundaries showed that listeners perceive two distinct categories, but also that the data is better explained if more prosodic categories, up to 8, are assumed. [Supported by NIH.]

Prosodic processing at the sentence level in infants

We investigate whether 8-month-old infants can detect prosodic cues relevant in sentence structuring. We recorded event-related potentials to examine online responses to the processing of prosodic boundaries. Prior studies in adults have validated the closure positive shift as reflecting prosodic boundary perception during speech processing. The current study shows that in the event-related potentials of 8-month-olds, a closure positive shift is elicited in relation to the prosodic boundaries in speech, suggesting that these infants are able to structure speech input into prosodic units on a neurophysiological basis similar to that seen in adults. A delay in latency of the infant closure positive shift, however, suggests that children's exploitation of prosodic boundaries for the segmentation of the speech stream is still developing.

Hemispheric specialisation in processing prosodic structures: Revisited

Background : Research addressing prosodic deficits in brain-damaged populations has concentrated on the specialised capabilities of the right and the left cerebral hemispheres in processing the global characteristics of prosody. This focus has been of interest in that the fundamental frequency (F0), duration and intensity acoustic characteristics within a prosodic structure can convey different linguistic and nonlinguistic information. Much of the research investigating this interesting phenomenon has produced conflicting results. As such, different theories have been proposed in an attempt to provide plausible explanations of the conflicting findings regarding hemispheric specialisation in processing prosodic structures. Aims : The purpose of this study was to examine one of the theories, the functional lateralisation theory, through four experiments that altered the linguistic and nonlinguistic functions across a range of prosodic structures. Methods & Procedures : Three groups of subjects participated in each of the four experiments: (1) eight subjects with LHD, (2) eight subjects with RHD, and (3) eight control subjects. The first experiment addressed the extent to which the processing of lexical stress differences would be lateralised to the left or right hemisphere by requiring listeners to determine the meanings and grammatical assignments of two-syllable words conveyed through stressed or unstressed syllables. In another linguistic condition, the second experiment placed demands on syntactic parsing operations by requiring listeners to parse syntactically ambiguous sentences which were disambiguated through the perception of prosodic boundaries located at syntactic junctures. A third linguistic condition required listeners to determine the categorical assignment of a speaker's intention of making a statement or asking a question conveyed through the prosodic structures. The fourth experiment was designed to determine hemispheric lateralisation in processing nonlinguistic prosodic structures. In this experiment, listeners were required to determine the emotional state of a speaker conveyed through the prosodic structures in sentences that contained semantic information which was either congruent or incongruent with the emotional content of the prosodic structures. Results : When subjects were asked to identify lexical stress differences (Experiment 1), syntactically ambiguous sentences (Experiment 2), and questions and statements (Experiment 3) conveyed through prosody, the LHD group demonstrated a significantly poorer performance than the control and RHD groups. When asked to identify emotions conveyed through prosody (Experiment 4), the RHD group demonstrated a significantly poorer performance than the control and LHD groups. Conclusion : These findings support the functional lateralisation theory that proposes a left hemisphere dominance for processing linguistic prosodic structures and a right hemisphere dominance for processing nonlinguistic prosodic structures.