Duration Cues Research Articles

Production and Comprehension of Prosodic Markers in Sign Language Imperatives.

In signed and spoken language sentences, imperative mood and the corresponding speech acts such as for instance, command, permission or advice, can be distinguished by morphosyntactic structures, but also solely by prosodic cues, which are the focus of this paper. These cues can express paralinguistic mental states or grammatical meaning, and we show that in American Sign Language (ASL), they also exhibit the function, scope, and alignment of prosodic, linguistic elements of sign languages. The production and comprehension of prosodic facial expressions and temporal patterns therefore can shed light on how cues are grammaticalized in sign languages. They can also be informative about the formal semantic and pragmatic properties of imperative types not only in ASL, but also more broadly. This paper includes three studies: one of production (Study 1) and two of comprehension (Studies 2 and 3). In Study 1, six prosodic cues are analyzed in production: temporal cues of sign and hold duration, and non-manual cues including tilts of the head, head nods, widening of the eyes, and presence of mouthings. Results of Study 1 show that neutral sentences and commands are well distinguished from each other and from other imperative speech acts via these prosodic cues alone; there is more limited differentiation among explanation, permission, and advice. The comprehension of these five speech acts is investigated in Deaf ASL signers in Study 2, and in three additional groups in Study 3: Deaf signers of German Sign Language (DGS), hearing non-signers from the United States, and hearing non-signers from Germany. Results of Studies 2 and 3 show that the ASL group performs significantly better than the other 3 groups and that all groups perform above chance for all meaning types in comprehension. Language-specific knowledge, therefore, has a significant effect on identifying imperatives based on targeted cues. Command has the most cues associated with it and is the most accurately identified imperative type across groups—indicating, we suggest, its special status as the strongest imperative in terms of addressing the speaker's goals. Our findings support the view that the cues are accessible in their content across groups, but that their language-particular combinatorial possibilities and distribution within sentences provide an advantage to ASL signers in comprehension and attest to their prosodic status.

Durational cues to stress, final lengthening, and the perception of rhythm

Binary stress languages have a well-known asymmetry between their tolerance of initial versus final lapse; the former being extremely rare and the latter being quite common. Lunden (to appear) proposes that final lengthening plays a role in this asymmetry, as the additional inherent phonetic duration of the final syllable can contribute to the continuation of a perceived rhythm, even in the absence of actual final stress. She notes this effect of final lengthening should only be available in languages that use duration as a cue to stress. However, some languages are described as having different cues to primary and secondary stress, and it is not clear which is more important for this perceptual effect. The results of four new studies show that final lengthening contributes to the perceptual rhythm of the word even when only one level of stress is cued with duration.

Cue restructuring in English u-fronting: The role of phonetics and phonology in feature-learning

Back tense /u/ is fronting in English in the Northeast US, which results in cue restructuring for the high front lax, back tense contrast (/u--I/). They are no longer distinguished by F2, but the F1 distinction between them is enhanced. In this paper I investigate whether this cue restructuring applies to the phonologically minimally different mid pair /o-E/. I present results from a perception experiment testing to what extent speakers use F1, F2, F3 and duration cues to distinguish between /u--I/ and /o--E/, respectively. Results show that while speakers use the new cues that are available for the /u-I/ contrast, this cue is not useful for the /o-E/, even though these sounds also differ in F1. F3 and duration are not used for either pair. This indicates that cue restructuring stemming from u-fronting does not happen on a featural level, therefore the experiment does not find evidence for a [+/-back] feature. By for a feature in a phonetically natural but phonologically inactive set, this work also contributes to research on mental representations.

Initial laryngeal neutralisation in Tyrolean

In the Southern Bavarian variety of Tyrolean, laryngeal contrasts undergo a typologically interesting process of neutralisation in word-initial position. We undertake an acoustic analysis of Tyrolean stops in word-initial, word-medial intersonorant and word-final contexts, as well as in obstruent clusters, investigating the role of the acoustic parameters VOT, prevoicing, closure duration and F0 and H1–H2* on following vowels in implementing contrast, if any. Results show that stops contrast word-medially via [voice] (supported by the acoustic cues of closure duration and F0), and are neutralised completely in word-final position and in obstruent clusters. Word-initially, neutralisation is subject to inter- and intraspeaker variability, and is sensitive to place of articulation. Aspiration plays no role in implementing laryngeal contrasts in Tyrolean.

Effects of bilingualism on cue weighting: How do bilingual children perceive the Dutch [ɑ]-[a:] contrast?

The effects of bilingualism on vowel perception and cue weighting behaviour have not been established definitively. What influence does heritage bilingualism have on cue weighting of spectral and durational cues? What role does the duration cue play in cue weighting behaviour of heritage bilinguals: is it universally accessible or related to the first language? Purpose: This study examines the perception and cue weighting of child heritage bilinguals to assess whether exposure to multiple acoustic systems has an effect on cue weighting. Design: Bilinguals with a language containing a durational vowel contrast (Moroccan-Arabic) or a non-durational contrast (Turkish) were tested in order to explore cue preference and cue weighting behaviour for the multiple cued Dutch [ɑ]-[a:] contrast: their alternate first language. Data and analysis: An identification task was performed for the Dutch [ɑ] and [a:]. The F1 and F2 were logarithmically manipulated, in equal steps for the spectral and durational cue, creating a seven-step continuum. The analysis revealed cue preference by examining cue usage and relative cue weight. Conclusions: Dutch monolinguals use both cues but assign more weight to the spectral cue. Moroccan-Arabic/Dutch heritage speaker (HS) bilinguals use both cues, but weigh the spectral cue more heavily. Turkish/Dutch HS bilinguals rely almost exclusively on the spectral cue. This suggests a transfer from the alternate first language onto the perception of Dutch, regardless of language dominance. Originality: Not much research on the cue weighting behaviour of school-aged heritage bilinguals has been conducted, as this age group is yet to develop their perceptual behaviour completely. The results of this case study show an influence on perceptual behaviour as a result of bilingualism. Significance: This study provides insight into the cue weighting behaviour and cue preference of school-aged heritage bilinguals.

A longitudinal study of individual differences in the acquisition of new vowel contrasts

This study explores how individuals’ second language cue weighting strategies change over time and across different contrasts. The study investigates the developmental changes in perceptual cue weighting of two English vowel contrasts (/i/-/ɪ/ and /ɛ/-/æ/) by adult and child Korean learners of English during their first year of immersion in Canada. Longitudinal results revealed that adult learners had an initial advantage in L2 perceptual acquisition over children at least for the /i/-/ɪ/ contrast, but after one year some children showed greater improvements especially on the more difficult /ɛ/-/æ/ contrast. Both groups of Korean learners showed different acquisition patterns between the two vowel contrasts: they used both spectral and duration cues to distinguish /i/-/ɪ/ but generally only duration to distinguish /ɛ/-/æ/. By examining cue weights over time, this study partially confirmed the hypothesized developmental stages for the acquisition of L2 vowels first proposed by Escudero (2000) for Spanish learners of English. However, some unpredicted patterns were also identified. Most importantly, the longitudinal results suggest that individual differences in cue weighting are not merely random variability in the learner’s response patterns, but are systematically associated with the developmental trajectories of individual learners and those trajectories vary according to vowel contrast.

Glottalisation as a cue to coda consonant voicing in Australian English

Recent research has suggested that some long vowels exhibit a constraint on voiceless coda induced shortening in Australian English. This constraint has the potential to compromise the vowel length cue to coda voicing, raising questions about how the coda stop voicing contrast is preserved if vowel duration cues are weakened. One possibility is that glottalisation and vowel duration are exploited in a trading relationship as cues to coda voicelessness. We conducted an apparent time study using a highly constrained dataset to determine whether vowel duration and the presence of glottalisation covary as cues to coda stop voicing and whether there is evidence of recent change to the weighting of these cues in Australian English. The incidence of glottalisation and temporal aspects of voiced and voiceless rhymes were analysed in the speech of male and female speakers from two different age groups. Results showed that younger speakers exhibited greater use of glottalisation in voiceless contexts in association with reduced coda voicing-related vowel duration cues compared to older speakers. These finding raise questions about the weighting of glottalisation and vowel duration as cues to coda stop voicing and may suggest change in progress regarding the management of voicing cues in the rhyme.

Vowel inventory size matters: assessing cue-weighting in L2 vowel perception

To examine whether L1 vowel inventory size could be a contributing factor to the use of temporal cues in L2 vowel perception, this study assessed the perception of English /i-ɪ/ by 66 learners of four different L1s: Danish, Portuguese, Catalan and Russian. The L2 learners performed a forced-choice identification task containing natural and duration-manipulated stimuli. Findings suggest that the participants’ over-reliance on duration cues seem to be partially related to their L1 vowel inventory size. The participants with the greatest L1 vowel inventory (Danish) demonstrated the most native-like vowel perception and the participants with the smallest L1 vowel inventory (Russian) over-relied on duration cues more than the other learners. Interestingly, the participants with somewhat comparable L1 vowel inventories (Portuguese and Catalan) performed similarly.

The role of segmental and durational cues in the processing of reduced words.

In natural conversations, words are generally shorter and they often lack segments. It is unclear to what extent such durational and segmental reductions affect word recognition. The present study investigates to what extent reduction in the initial syllable hinders word comprehension, which types of segments listeners mostly rely on, and whether listeners use word duration as a cue in word recognition. We conducted three experiments in Dutch, in which we adapted the gating paradigm to study the comprehension of spontaneously uttered conversational speech by aligning the gates with the edges of consonant clusters or vowels. Participants heard the context and some segmental and/or durational information from reduced target words with unstressed initial syllables. The initial syllable varied in its degree of reduction, and in half of the stimuli the vowel was not clearly present. Participants gave too short answers if they were only provided with durational information from the target words, which shows that listeners are unaware of the reductions that can occur in spontaneous speech. More importantly, listeners required fewer segments to recognize target words if the vowel in the initial syllable was absent. This result strongly suggests that this vowel hardly plays a role in word comprehension, and that its presence may even delay this process. More important are the consonants and the stressed vowel.

Blocking by fixed and variable stimuli: Effects of stimulus distribution on blocking.

An experiment with rats compared the ability of fixed and variable duration cues to produce blocking. Rats in group B (Blocking) were trained that both fixed- (F) and variable- (V) duration cues would be followed by food delivery. In a subsequent training stage F and V continued to be reinforced, but F was accompanied by X, and V by Y. In the test phase responding to X and Y was examined. Control group O (Overshadowing) received identical treatment, except that F and V were nonreinforced in the first training stage. In group B there was evidence for blocking, but only of X, which had been conditioned in compound with the fixed-duration F; there was no evidence for blocking of Y, which had been conditioned in compound with the variable-duration V. It is suggested that this result may occur because fixed cues reach a higher, more stable asymptote of associative strength than do their variable equivalents.

Acoustic correlates of focus in Marathi: Production and perception

Focus or prominence is an important linguistic function of prosody. The acoustic realisation of prominence in an utterance, in most languages, involves one or more acoustic dimensions while affecting one or more words in the utterance. It is of interest to identify the acoustic correlates as well as their possible interaction in the production and perception of focus. In this article, we consider the acoustics of focus in Marathi. Previous studies on Hindi, the more researched member of the Indo-Aryan family, have reported that the well-known rising F0 pattern on non-final content words in an utterance becomes hyper-articulated when the word is in focus. The associated F0 excursion, duration and intensity increase and are accompanied by post-focal compression of pitch range. A preliminary goal of the present study was to verify whether Marathi exhibits similar behaviour. We used Subject–Object–Verb (SOV) structured utterances with elicited focus on each word by 12 native Marathi speakers. We observed that each narrow focus location is accompanied by a distinct set of local and global acoustic correlates in F0, duration and intensity which closely parallel previous observations on Hindi. F0 cues were also examined via the accent command amplitudes of the Fujisaki model. F0 range, duration and intensity were found to vary significantly with focus condition prompting a study to examine their relative importance in the perceptual judgement of focus. Perception testing with synthetically manipulated utterances revealed that duration cues are interpreted in a categorical manner, relatively uninfluenced by the pitch cues. Only when duration is ambiguous, does the on-focus F0 cue appear to play a role. An explanation for this may lie in the normal F0-rise characteristic of the content words in Marathi, making pitch a less dependable functional cue for focus.

Mandarin tone identification with subsegmental cues in single vowels and isolated words

ABSTRACTThis study investigated the contributions of subsegmental cues [i.e., vowel center, vowel onset, and consonant (C)-vowel (V) transition] to Mandarin tone identification. In Experiment 1, single vowels were edited to preserve different proportions of vowel centers or vowel onsets. In Experiment 2, isolated Mandarin words were processed to produce two conditions of consonant plus C-V transition, and C-V transition. The synthesized stimuli were presented to normal-hearing native-Mandarin listeners for tone identification. Experimental results showed that, at the same proportion, vowel centers carried more information than vowel onsets for tone identification. The effect of vowel onsets on tone identification depended on the context of testing materials, with increased identification accuracy from single vowels to C-V transitions in isolated words. The duration of subsegmental cues could potentially predict the accuracy of subsegment-based tone identification.

Typological variation in the phonetic realization of lexical and phrasal stress: Southern British English vs. Tunisian Arabic

Results of phonetic experiments on the acoustic correlates of lexical stress (word-level prominence) and phrasal stress (phrase-level prominence = accent) as two separate concepts in two typologically different languages, Southern British English (SBE) and Tunisian Arabic (TA), are reported in this study. Because of the confusion in the literature between the terms stress and accent, their acoustic correlates were muddled, too. To avoid this confusion, the data in this study are elicited using an experimental paradigm which allows careful investigation of the correlates of each concept independently. The duration, spectral balance, and vowel quality cues are measured. Results show cross-linguistic similarities and differences between the two languages. Unlike most world languages, duration in TA is not a correlate of stress. It is rather a correlate of accent. In the absence of focus on the target words in TA, the only phonetic characteristics of lexical stress that come in the foreground are spectral balance and F1 lowering. However, when the word is focused, Tunisian speakers rely mainly on duration and spectral balance to signal accent. SBE signals stress through three acoustic correlates which are duration, spectral balance, and vowel quality. More similarity is found for accent detection between speakers of the two languages.

The perception of emotion and focus prosody with varying acoustic cues in cochlear implant simulations with varying filter slopes.

This study aimed to find the optimal filter slope for cochlear implant simulations (vocoding) by testing the effect of a wide range of slopes on the discrimination of emotional and linguistic (focus) prosody, with varying availability of F0 and duration cues. Forty normally hearing participants judged if (non-)vocoded sentences were pronounced with happy or sad emotion, or with adjectival or nominal focus. Sentences were recorded as natural stimuli and manipulated to contain only emotion- or focus-relevant segmental duration or F0 information or both, and then noise-vocoded with 5, 20, 80, 120, and 160 dB/octave filter slopes. Performance increased with steeper slopes, but only up to 120 dB/octave, with bigger effects for emotion than for focus perception. For emotion, results with both cues most closely resembled results with F0, while for focus results with both cues most closely resembled those with duration, showing emotion perception relies primarily on F0, and focus perception on duration. This suggests that filter slopes affect focus perception less than emotion perception because for emotion, F0 is both more informative and more affected. The performance increase until extreme filter slope values suggests that much performance improvement in prosody perception is still to be gained for CI users.

Spectro-temporal cues for perceptual recovery of reduced syllables from continuous, casual speech

Function words may be highly reduced, with little to no discontinuity marking their onsets to cue their segmentation from continuous speech. The present study investigated whether reduced function words lacking onset discontinuities have residual timing cues that could be used for word segmentation. Participants (n = 51) briefly viewed sentences and spoke them from memory to elicit casual speech. They were randomly assigned to either a “function-word present” condition (n = 29) in which experimental items contained a critical function word expected to frequently blend spectrally with context, or a “function-word absent” set (n = 22) with phonetically matched items lacking the critical word. Acoustic analyses confirmed that in “function-word present” sentences, critical words lacked detectable onset discontinuities 60% of the time. Critically, in the “function-word present” condition, portions of speech containing critical function words were longer, both in terms of absolute duration and normalized for context speech rate, compared with matched portions in the “function-word absent” condition, even when the former were highly reduced and lacked onset discontinuities. These findings suggest that relative duration cues provide substantial information which may be used by listeners for segmentation of highly reduced syllables from continuous speech. [Work supported by NSF Grant BCS-1431063.]

Musical Sophistication and the Effect of Complexity on Auditory Discrimination in Finnish Speakers.

Musical experiences and native language are both known to affect auditory processing. The present work aims to disentangle the influences of native language phonology and musicality on behavioral and subcortical sound feature processing in a population of musically diverse Finnish speakers as well as to investigate the specificity of enhancement from musical training. Finnish speakers are highly sensitive to duration cues since in Finnish, vowel and consonant duration determine word meaning. Using a correlational approach with a set of behavioral sound feature discrimination tasks, brainstem recordings, and a musical sophistication questionnaire, we find no evidence for an association between musical sophistication and more precise duration processing in Finnish speakers either in the auditory brainstem response or in behavioral tasks, but they do show an enhanced pitch discrimination compared to Finnish speakers with less musical experience and show greater duration modulation in a complex task. These results are consistent with a ceiling effect set for certain sound features which corresponds to the phonology of the native language, leaving an opportunity for music experience-based enhancement of sound features not explicitly encoded in the language (such as pitch, which is not explicitly encoded in Finnish). Finally, the pattern of duration modulation in more musically sophisticated Finnish speakers suggests integrated feature processing for greater efficiency in a real world musical situation. These results have implications for research into the specificity of plasticity in the auditory system as well as to the effects of interaction of specific language features with musical experiences.

Realisation of voicing by French-speaking CI children after long-term implant use: An acoustic study

ABSTRACTStudies of speech production in French-speaking cochlear-implanted (CI) children are very scarce. Yet, difficulties in speech production have been shown to impact the intelligibility of these children. The goal of this study is to understand the effect of long-term use of cochlear implant on speech production, and more precisely on the coordination of laryngeal-oral gestures in stop production. The participants were all monolingual French children: 13 6;6- to 10;7-year-old CI children and 20 age-matched normally hearing (NH) children. We compared /p/, /t/, /k/, /b/, /d/ and /g/ in word-initial consonant-vowel sequences, produced in isolation in two different tasks, and we studied the effects of CI use, vowel context, task and age factors (i.e. chronological age, age at implantation and duration of implant use). Statistical analyses show a difference in voicing production between groups for voiceless consonants (shorter Voice Onset Times for CI children), with significance reached only for /k/, but no difference for voiced consonants. Our study indicates that in the long run, use of CI seems to have limited effects on the acquisition of oro-laryngeal coordination needed to produce voicing, except for specific difficulties located on velars. In a follow-up study, further acoustic analyses on vowel and fricative production by the same children reveal more difficulties, which suggest that cochlear implantation impacts frequency-based features (second formant of vowels and spectral moments of fricatives) more than durational cues (voicing).

Cross-linguistic differences in the use of durational cues for the segmentation of a novel language.

It is widely accepted that duration can be exploited as phonological phrase final lengthening in the segmentation of a novel language, i.e., in extracting discrete constituents from continuous speech. The use of final lengthening for segmentation and its facilitatory effect has been claimed to be universal. However, lengthening in the world languages can also mark lexically stressed syllables. Stress-induced lengthening can potentially be in conflict with right edge phonological phrase boundary lengthening. Thus the processing of durational cues in segmentation can be dependent on the listener's linguistic background, e.g., on the specific correlates and unmarked location of lexical stress in the native language of the listener. We tested this prediction and found that segmentation by both German and Basque speakers is facilitated when lengthening is aligned with the word final syllable and is not affected by lengthening on either the penultimate or the antepenultimate syllables. Lengthening of the word final syllable, however, does not help Italian and Spanish speakers to segment continuous speech, and lengthening of the antepenultimate syllable impedes their performance. We have also found a facilitatory effect of penultimate lengthening on segmentation by Italians. These results confirm our hypothesis that processing of lengthening cues is not universal, and interpretation of lengthening as a phonological phrase final boundary marker in a novel language of exposure can be overridden by the phonology of lexical stress in the native language of the listener.

Processing of word-level stress by Mandarin-speaking second language learners of English

ABSTRACTThis study investigates whether second language learners’ processing of stress can be explained by the degree to which suprasegmental cues contribute to lexical identity in the native language. It focuses on Standard Mandarin, Taiwan Mandarin, and American English listeners’ processing of stress in English nonwords. In Mandarin, fundamental frequency contributes to lexical identity by signaling lexical tones, but only in Standard Mandarin does duration distinguish stressed–unstressed and stressed–stressed words. Participants completed sequence-recall tasks containing English disyllabic nonwords contrasting in stress. Experiment 1 used natural stimuli; Experiment 2 used resynthesized stimuli that isolated fundamental frequency and duration cues. Experiment 1 revealed no difference among the groups; in Experiment 2, Standard Mandarin listeners used duration more than Taiwan Mandarin listeners did. These results are interpreted within a cue-weighting theory of speech perception.

Shifting Perceptual Weights in L2 Vowel Identification after Training.

Difficulties with second-language vowel perception may be related to the significant challenges in using acoustic-phonetic cues. This study investigated the effects of perception training with duration-equalized vowels on native Chinese listeners’ English vowel perception and their use of acoustic-phonetic cues. Seventeen native Chinese listeners were perceptually trained with duration-equalized English vowels, and another 17 native Chinese listeners watched English videos as a control group. Both groups were tested with English vowel identification and vowel formant discrimination before training, immediately after training, and three months later. The results showed that the training effect was greater for the vowel training group than for the control group, while both groups improved their English vowel identification and vowel formant discrimination after training. Moreover, duration-equalized vowel perception training significantly reduced listeners’ reliance on duration cues and improved their use of spectral cues in identifying English vowels, but video-watching did not help. The results suggest that duration-equalized English vowel perception training may improve non-native listeners’ English vowel perception by changing their perceptual weights of acoustic-phonetic cues.