Acoustic markers of syllabic stress in Spanish excellent oesophageal speakers

The purpose of this investigation is to explore the use by Spanish excellent oesophageal speakers of acoustic cues to mark syllabic stress. The speech material has consisted of five pairs of disyllabic words which only differed in stress position. Total 44 oesophageal and 9 laryngeal speakers were recorded and a computerised designed ad hoc perceptual test was run in order to assess the accurate realisation of stress. The items produced by eight excellent oesophageal speakers with highest accuracy levels in the perception experiment were analysed acoustically with Praat, to be compared with the laryngeal control group. Measures of duration, fundamental frequency, spectral balance and overall intensity were taken for each target vowel and syllable. Results revealed that Spanish excellent oesophageal speakers were able to retain appropriate acoustic relations between stressed and unstressed syllables. Although spectral balance revealed as a strong cue for syllabic stress in the two voicing modes, a different hierarchy of acoustic cues in each voicing mode was found.     

Acoustic markers of prosodic boundaries in Spanish spontaneous alaryngeal speech

Prosodic information aids segmentation of the continuous speech signal and thereby facilitates auditory speech processing. Durational and pitch variations are prosodic cues especially necessary to convey prosodic boundaries, but alaryngeal speakers have inconsistent control over acoustic parameters such as F0 and duration, being as a result noisy and less intelligible than normal speech. This case study has investigated whether one Spanish alaryngeal speaker proficient in both oesophageal and tracheoesophageal speech modes used the same acoustic cues for prosodic boundaries in both types of voicing. Pre-boundary lengthening, F0-excursions and pausing (number of pauses and position) were measured in spontaneous speech samples, using Praat. The acoustic analysis has revealed that the subject has relied on a different combination of cues in each type of voicing to convey the presence of prosodic boundaries.     

Acoustic markers of prosodic boundaries in Spanish spontaneous alaryngeal speech

Prosodic information aids segmentation of the continuous speech signal and thereby facilitates auditory speech processing. Durational and pitch variations are prosodic cues especially necessary to convey prosodic boundaries, but alaryngeal speakers have inconsistent control over acoustic parameters such as F0 and duration, being as a result noisy and less intelligible than normal speech. This case study has investigated whether one Spanish alaryngeal speaker proficient in both oesophageal and tracheoesophageal speech modes used the same acoustic cues for prosodic boundaries in both types of voicing. Pre-boundary lengthening, F0-excursions and pausing (number of pauses and position) were measured in spontaneous speech samples, using Praat. The acoustic analysis has revealed that the subject has relied on a different combination of cues in each type of voicing to convey the presence of prosodic boundaries.     

Prosodic boundaries in alaryngeal speech

Alaryngeal speakers (speakers in whom the larynx has been removed) have inconsistent control over acoustic parameters such as F(0) and duration. This study investigated whether proficient tracheoesophageal and oesophageal speakers consistently convey phrase boundaries. It was further investigated if these alaryngeal speakers used the same hierarchy of acoustic boundary cues that is found in normal speakers. A perception experiment revealed that listeners identified prosodic boundaries less accurately in oesophageal speakers. Acoustic analyses showed that laryngeal speakers used pre-boundary lengthening and pitch movements at phrase boundaries, as expected. Tracheoesophageal speakers used pre-boundary-lengthening and pauses and oesophageal speakers used pauses to convey phrase boundaries. Two oesophageal speakers also paused inappropriately, within phrases. Although these two speakers differentiated between air-injection and prosodic pauses, listeners were unable to tell the two types of pauses apart. Alaryngeal speakers might benefit from therapy that specifically teaches them how to optimize their prosodic abilities.     

Temporal control in the voicing contrast: Evidence from surgery-related apraxia of speech

ABSTRACT

The goal of this study was to investigate the phonetic realisation of the voicing feature in two tumour resection-related Spanish speakers with apraxia of speech. Temporal parameters related to the phonological contrast of voicing in Spanish have been analysed for intervocalic voiced and voiceless obstruents embedded in isolated words and nonwords, and compared with data collected from healthy speakers. Results indicate that in devoiced productions, where VOT values fitted the ‘voiceless stops’ category, vowel duration values matched those of voiced stops and suggested the preservation of contextual voicing cues. An attempt at preserving a consonant/vowel duration ratio consistent with aerodynamic predictions for voicing contrast has been observed in apraxic correct production as well as in devoicing errors, but not in the control group, which could be interpreted as a compensatory mechanism.     

Vowel duration as a cue to postvocalic stop voicing in aphasia and apraxia of speech

Background: In American English, vowel duration is, on average, longer preceding postvocalic voiced stops than preceding postvocalic voiceless stops. Preliminary investigations have reported a preservation of this acoustic contrast for speakers with aphasia and apraxia of speech (AOS) on the basis of mean data. However, clinical interpretation of the available research is difficult due to lack of attention to the range of performance among and within speakers from both normal and disordered populations. Concurrent perceptual analysis is warranted to evaluate functional implications of acoustic variations, but standard approaches using a single listener and presentation may not be sufficiently sensitive to reveal subtle variations. Aims: (1) To determine whether aphasic and apraxic speakers produce a normal vowel duration differentiation between voiced and voiceless postvocalic stops. (2) To explore whether the produced vowel duration variations are associated with predicted perceptual effects. Methods & Procedures: Eight speakers with coexisting aphasia and AOS, eight with aphasia and no AOS, and eight normal control speakers produced 24 repetitions of the words “had” and “hat” in a short carrier phrase. For each utterance, the duration of the vowel was measured. Perceptual testing was conducted using three normal listeners and a forced‐choice perceptual identification paradigm. Outcomes & Results: As expected, all normal speakers, and most aphasic and apraxic speakers, displayed a mean vowel duration distinction between the voicing cognates. The magnitude of the distinction did not differ across groups. Instead, there was substantial inter‐speaker variability in the magnitude of duration contrast in all three groups. Some aphasic speakers with and without AOS did not distinguish in vowel duration between voicing cognates, and others displayed bimodal, but overlapping, distributions for /d/ and /t/. Results of the perceptual identification experiment indicated that there was good, but not perfect, agreement between variations in vowel duration and voicing perception and that several utterances produced by aphasic and apraxic speakers were perceptually ambiguous. Conclusions: (1) Although the mean duration for vowels preceding voiced and voiceless stops may be indistinguishable from normal, several abnormal acoustic patterns are found among individual aphasic speakers both with and without AOS. (2) The magnitude of acoustic distinction can vary considerably across normal speakers and this variation must be considered when evaluating disordered speech. (3) Perceptual identification testing facilitates the interpretation of acoustic data, particularly when the two levels of analysis are matched on an utterance‐by‐utterance basis. (4) Perceptual ambiguity can be demonstrated in disordered speech through perceptual identification testing.     

Voicing status of word final plosives in Friedreich's Ataxia dysarthria

In a previous study, the authors identified final plosive voicing contrast as the highest single error source in dysarthria associated with Friedreich's Ataxia in a group of Irish English‐speaking participants. This study aimed to determine the acoustic features underlying misperceptions of voicing status and implications for clinical management. Words with final plosives were extracted from recordings of ten speakers with Friedreich's Ataxia. Various measures of the syllable rhyme were compared with intelligibility scores. Vowel duration, voicing in the closure, F1 frequency at mid‐vowel and a drop in F1 at vowel termination accounted for 58% of the variance in the relevant intelligibility scores, with vowel duration being most heavily implicated. While inappropriate vowel duration is the factor most likely to lead to misperceptions of final plosive voicing status, other factors may overcome its effect. Therapeutic intervention with this population should be based on a comparison of intelligibility assessment with acoustic measurement.     

Voicing status of word final plosives in Friedreich's Ataxia dysarthria

In a previous study, the authors identified final plosive voicing contrast as the highest single error source in dysarthria associated with Friedreich's Ataxia in a group of Irish English-speaking participants. This study aimed to determine the acoustic features underlying misperceptions of voicing status and implications for clinical management. Words with final plosives were extracted from recordings of ten speakers with Friedreich's Ataxia. Various measures of the syllable rhyme were compared with intelligibility scores. Vowel duration, voicing in the closure, F1 frequency at mid-vowel and a drop in F1 at vowel termination accounted for 58% of the variance in the relevant intelligibility scores, with vowel duration being most heavily implicated. While inappropriate vowel duration is the factor most likely to lead to misperceptions of final plosive voicing status, other factors may overcome its effect. Therapeutic intervention with this population should be based on a comparison of intelligibility assessment with acoustic measurement.     

Analogy between laryngeal gesture in Mongolian Long Song and supracricoid partial laryngectomy

This article reports the results of a multiparametrical analysis of Mongolian Long Song, characterised by multiple ornamentation and shows the similarities between the laryngeal behaviour observed during these ornamentations and the compensatory gesture produced by patients after supracricoid partial laryngectomy. This study includes (1) a physiological analysis of videofiberscopic laryngeal data from a healthy Mongolian singer and from three non-singer French-speaking clinical patients; and (2) an acoustical analysis (fundamental frequency and intensity). For the singer, the fiberoptic analysis showed two main laryngeal behaviours in producing ornamentations: (1) ‘lyrical’ vibratos mobilising the entire laryngeal block; (2) ‘Mongolian’ trills with essentially supraglottic movements, the arytenoids being mobilised independently of the rest of the laryngeal block. Patients demonstrated similar aryepiglottic trilling to fulfil a function of voicing. The acoustic analysis showed that the fundamental frequency and the intensity were in phase for vibrato, contrary to the ‘Mongolian’ trills which were in opposite phase, underlying a change of laryngeal vibratory mechanisms.     

A perceptual study of the voicing feature of stop consonants after type II and III laser cordectomies

This article deals with the intelligibility of stop consonants in onset position (initial and intervocalic) as pronounced by 10 French speakers treated by a type II or III cordectomy. These surgeries cause a less efficient glottal closure and a vibratory asymmetry. The voicing contrast in consonants may be altered. The patients’ vocal samples were made up of non-words of the CVCVCVC type, where C = /p, t, k, b, d, g/ and V = /a, i, u/(n = 360), and were given to 22 French listeners for evaluation. Two identification tests were created and the listeners were asked to choose the consonants they thought they recognized (n = 7920). The results were presented in the form of a confusion matrix highlighting possible confusions of voicing and/or places of articulation. We showed high identification rates of consonants, which revealed an intact voicing contrast in this dysphonic population.     

The effect of esomeprazole 20 mg twice daily on acoustic and perception parameters of the voice in laryngopharyngeal reflux

Background Randomized, placebo‐controlled studies have failed to demonstrate a significant treatment effect for laryngopharyngeal reflux (LPR) using traditional clinical endpoints. We compared the effect of esomeprazole 20 mg twice daily (b.i.d.) vs placebo on voice and acoustic‐related measures in patients with LPR. Methods Patients with LPR underwent endoscopy and pH testing. Subsequently, patients underwent videostroboscopic recordings of the larynx, acoustic voice and speech analysis. A voice use and quality diary and oesophageal symptom diary were completed at baseline. Thereafter, patients were randomized to esomeprazole 20 mg twice daily vs placebo for 3 months. The voice use and quality diary and oesophageal symptom dairy were repeated during the last week of treatment. Videostroboscopy and acoustic voice and speech analysis were also performed at the end of treatment. Key Results Twenty‐four patients were randomized to the esomeprazole group and 17 to the placebo group. There was no significant difference in videostroboscopic reflux finding scores from baseline to post‐treatment. Acoustic measures also failed to demonstrate significant differences within the same or between groups, even when a sub‐group analysis of patients with endoscopically documented oesophageal inflammation at baseline was performed. Additionally, no significant differences were found between groups when using voice use and quality diary. Conclusions & Inferences Use of more specific laryngeal functional parameters such as voice‐related acoustic measures of pitch range, fundamental frequency and intensity also failed to demonstrate a significant response to proton pump inhibitor treatment as compared to placebo in patients with suspected LPR.     

Acoustic phenotypes for speech-genetics studies: toward an acoustic marker for residual /s/ distortions

Findings in a prior study series indicate that acoustic markers may have the requisite sensitivity and specificity to discriminate speakers with histories of several types of speech disorders, one of which is posited to be genetically inherited. The present study in this series compares acoustic data from three groups of adolescent speakers. Group 1 speakers had residual dentalized /s/ distortions in conversational speech and histories of significant age-inappropriate deletion and substitution errors. Group 2 speakers also had residual dentalized /s/ distortions in conversational speech, but their speech histories were limited to dentalized distortions of /s/ and other fricatives/affricates. Group 3 speakers had typical speech on assessment and no histories of speech errors. Owing to the limited number of perceptually dentalized /s/ tokens produced by Groups 1 and 2 speakers in a phrase-level speech task, acoustic analyses were completed on /s/ tokens transcribed as correct for speakers in all groups. Moments analyses of /s/ spectra in three words with /s/-initial clusters yielded statistically significant differences and consistent trends for mean spectral frequency and spectral variance for Group 1 compared with Group 2 speakers. These findings for perceptually normal /s/ tokens are interpreted as additional support for the potential of acoustic markers to discriminate speakers' speech-error histories. The discussion considers possible developmental and normalization correlates of the acoustic findings for speakers with each of the two types of speech-error histories studied in this paper.     

Auditory perceptual evaluation of rhythm-manipulated and resynthesized sentence utterances obtained from cerebellar patients and normal speakers: A preliminary report

Alterations of the temporal structure of spoken utterances in terms of lengthened acoustic segments and increased syllabic isochrony seem to represent a salient feature of ataxic dysarthria. The present study addresses the question of whether systematic manipulations of the durational aspects of the acoustic speech signal yield an improvement of perceived dysarthric deficits. Different variants of speech rhythm were imposed on sentence utterances obtained from two patients with ataxic dysarthria and two normal control speakers. For the sake of comparability the pitch contours were standardized by means of linearly interpolated stylized versions. The introduced manipulations significantly influenced the ratings of perceived slowness, dysfluency, and rhythmic adequacy. With respect to estimates of overall intelligibility and naturalness, however, ataxic-dysarthric utterances did not benefit from any synthetic changes. By contrast, utterances of normal speakers were rated less intelligible and somewhat more unnatural when resynthesized with an ataxic rhythm. These results indicate that durational factors play a minor role with respect to the overall speech impairment of ataxic speakers.     

Phonetic detail and lateralization of reading‐related inner speech and of auditory and somatosensory feedback processing during overt reading

Phonetic detail and lateralization of inner speech during covert sentence reading as well as overt reading in 32 right‐handed healthy participants undergoing 3T fMRI were investigated. The number of voiceless and voiced consonants in the processed sentences was systematically varied. Participants listened to sentences, read them covertly, silently mouthed them while reading, and read them overtly. Condition comparisons allowed for the study of effects of externally versus self‐generated auditory input and of somatosensory feedback related to or independent of voicing. In every condition, increased voicing modulated bilateral voice‐selective regions in the superior temporal sulcus without any lateralization. The enhanced temporal modulation and/or higher spectral frequencies of sentences rich in voiceless consonants induced left‐lateralized activation of phonological regions in the posterior temporal lobe, regardless of condition. These results provide evidence that inner speech during reading codes detail as fine as consonant voicing. Our findings suggest that the fronto‐temporal internal loops underlying inner speech target different temporal regions. These regions differ in their sensitivity to inner or overt acoustic speech features. More slowly varying acoustic parameters are represented more anteriorly and bilaterally in the temporal lobe while quickly changing acoustic features are processed in more posterior left temporal cortices. Furthermore, processing of external auditory feedback during overt sentence reading was sensitive to consonant voicing only in the left superior temporal cortex. Voicing did not modulate left‐lateralized processing of somatosensory feedback during articulation or bilateral motor processing. This suggests voicing is primarily monitored in the auditory rather than in the somatosensory feedback channel. Hum Brain Mapp 38:493–508, 2017. © 2016 Wiley Periodicals, Inc.     

Acoustic phenotypes for speech-genetics studies: toward an acoustic marker for residual /s/ distortions

Findings in a prior study series indicate that acoustic markers may have the requisite sensitivity and specificity to discriminate speakers with histories of several types of speech disorders, one of which is posited to be genetically inherited. The present study in this series compares acoustic data from three groups of adolescent speakers. Group 1 speakers had residual dentalized /s/ distortions in conversational speech and histories of significant age-inappropriate deletion and substitution errors. Group 2 speakers also had residual dentalized /s/ distortions in conversational speech, but their speech histories were limited to dentalized distortions of /s/ and other fricatives/affricates. Group 3 speakers had typical speech on assessment and no histories of speech errors. Owing to the limited number of perceptually dentalized /s/ tokens produced by Groups 1 and 2 speakers in a phrase-level speech task, acoustic analyses were completed on /s/ tokens transcribed as correct for speakers in all groups. Moments analyses of /s/ spectra in three words with /s/-initial clusters yielded statistically significant differences and consistent trends for mean spectral frequency and spetcral variance for Group 1 compared with Group 2 speakers. These findings for perceptually normal /s/ tokens are interpreted as additional support for the potential of acoustic markers to discriminate speakers' speech-error histories. The discussion considers possible developmental and normalization correlates of the acoustic findings for speakers with each of the two types of speech-error histories studied in this paper.     

Perceptual comparison of neoglottal, oesophageal and normal speech.

The sex, normality, intelligibility, rate, rhythm and intonation of 44 neoglottal, oesophageal and normal speakers have been judged by a panel of 10 trained listeners. It was found that the sex of the alaryngeal speakers was perceived correctly much less reliably than that of the normal speakers. Neoglottal speakers were rated more normal and intelligible than oesophageal speakers. The speaking rate of neoglottal speakers was judged not to be significantly different from that of normal speakers. Neoglottal speakers were considered more fluent and to have better intonation than the other alaryngeal speakers. Thus neoglottal speakers were found, on average, to be as good as or better than good oesophageal speakers in each of the respects of which judgements were made.     

Lexical tone and stuttering in Cantonese

Cantonese is a tone language, in which the variation of the fundamental frequency contour of a syllable can change meaning. There are six different lexical tones in Cantonese. While research with Western languages has shown an association between stuttering and syllabic stress, nothing is known about whether stuttering in Cantonese speakers is associated with one or more of the six lexical tones. Such an association has been reported in conversational speech in Mandarin, which is also a tone language, but which varies markedly from Cantonese. Twenty-four native Cantonese-speaking adults who stutter participated in this study, ranging in age from 18–33 years. There were 18 men and 6 women. Participants read aloud 13 Cantonese syllables, each of which was produced with six contrastive lexical tones. All 78 syllables were embedded in the same carrier sentence, to reduce the influence of suprasegmental or linguistic stress, and were presented in random order. No significant differences were found for stuttering moments across the six lexical tones. It is suggested that this is because lexical tones, at least in Cantonese, do not place the task demands on the speech motor system that typify varying syllabic stress in Western languages: variations not only in fundamental frequency, but also in duration and intensity. The findings of this study suggest that treatments for adults who stutter in Western languages, such as speech restructuring, can be used with Cantonese speakers without undue attention to lexical tone.     

Quantifying dysphonia severity using a spectral/cepstral-based acoustic index: Comparisons with auditory-perceptual judgements from the CAPE-V

This study investigated the relationship between acoustic spectral/cepstral measures and listener severity ratings in normal and disordered voice samples. CAPE-V sentence samples and the vowel /ɑ/were elicited from eight normal speakers and 24 patients with varying degrees of dysphonia severity. Samples were analysed for measures of the cepstral peak prominence (CPP), the ratio of low-to-high spectral energy, and their respective standard deviations. Perceptual ratings of overall severity were also obtained for all samples. Results showed that all acoustic variables combined in a four-factor model which correlated with perceived severity with R = 0.81 (R² = 0.65). For the vowel /ɑ/, a five-factor model incorporating all acoustic variables and gender correlated with perceived severity with R = 0.96 (R² = 0.91). Results indicate that a strong relationship between perceptual and acoustic estimates of dysphonia severity can be achieved in both continuous speech and vowel contexts using a model incorporating spectral/cepstral measures.     

Perceptual and acoustic analysis of lexical stress in Greek speakers with dysarthria

The study reported in this paper investigated the abilities of Greek speakers with dysarthria to signal lexical stress at the single word level. Three speakers with dysarthria and two unimpaired control participants were recorded completing a repetition task of a list of words consisting of minimal pairs of Greek disyllabic words contrasted by lexical stress location only. Fourteen listeners were asked to determine the attempted stress location for each word pair. Acoustic analyses of duration and intensity ratios, both within and across words, were undertaken to identify possible acoustic correlates of the listeners’ judgments concerning stress location. Acoustic and perceptual data indicate that while each participant with dysarthria in this study had some difficulty in signaling stress unambiguously, the pattern of difficulty was different for each speaker. Further, it was found that the relationship between the listeners’ judgments of stress location and the acoustic data was not conclusive.     

Precision of fricative production in aphasia and apraxia of speech: A perceptual and acoustic study

We examined the precision of fricative place of articulation production in speakers with aphasia and apraxia of speech. Articulatory precision was defined based on acoustic consistency across repeated productions of the same target words and on the acoustic distinction between similar fricative targets. Ten aphasic speakers with apraxia of speech, ten aphasic speakers without apraxia of speech, and ten normal control speakers produced words beginning with voiceless alveolar and palatal fricatives. The Bark transformed first spectral moment was computed in the middle of the fricative. For normal speakers, this measure varied little across repetitions and the target fricatives were clearly distinguished. For aphasic speakers with apraxia of speech, there was substantial spectral variability and overlap between targets. A similar pattern was found for aphasic speakers without apraxia of speech, although the effects were smaller in magnitude. Among these aphasic speakers, the greatest degree of spectral overlap was seen in speakers with low single-word intelligibility scores. The observed spectral imprecision is consistent with impaired phoneticmotor control, not only in the temporal, but also in the spatial domain of speech production.