An Efficacy Study of Voice Quality Using Cepstral Analyses of Phonation in Parkinson's Disease before and after SPEAK-OUT!®

INTRODUCTION

SPEAK-OUT!® is a behavioral treatment for hypokinetic dysarthria in persons with Parkinson's disease (PD) that has become an alternative to the gold-standard Lee Silverman Voice Treatment (LSVT) in recent years. Acoustic evaluation of the efficacy of SPEAK-OUT!® therapy has focused on prosody. The purpose of this study was to investigate SPEAK-OUT!® efficacy in terms of vocal quality and its impact on quality of life. Vocal quality was measured acoustically using cepstral peak prominence (CPP) analysis and the Acoustic Voice Quality Index (AVQI) and perceptually using clinical ratings of speech performance. Impact on quality of life was measured with the Voice Handicap Index (VHI) and Voice-Related Quality of Life (V-RQOL). An additional goal of this study was to investigate whether dysarthria severity and disease duration were predictive of changes in voice quality due to SPEAK-OUT!®.

METHODS

Pre- and post-therapy data included PD participants' acoustic and perceptual ratings of audio recordings. Demographic data included age, sex, diagnosis, duration of PD, and severity of dysarthria.

RESULTS

Participants achieved significant improvement in the vowel and sentence CPP smoothed (CPPS) mean score as well as in their AVQI score post SPEAK-OUT!® treatment. Improvements in AVQI correlated negatively with disease duration and positively with dysarthria severity.

DISCUSSION/CONCLUSION

SPEAK-OUT!® is effective in improving voice quality in patients with hypokinetic dysarthria due to idiopathic PD. Patients with more severe dysarthria and with a shorter disease duration may benefit the most, supporting earlier intervention. As for the type of measurement, AVQI combines acoustics from both vowel and sentence contexts and may therefore be the measure of choice over CPPS (vowel) or CPPS (sentence).

Prosody and Spoken Word Recognition in Early and Late Spanish-English Bilingual Individuals

PURPOSE

This study was conducted to compare the influence of word properties on gated single-word recognition in monolingual and bilingual individuals under conditions of native and nonnative accent and to determine whether word-form prosody facilitates recognition in bilingual individuals.

METHOD

Word recognition was assessed in monolingual and bilingual participants when English words were presented with English and Spanish accents in 3 gating conditions: onset only, onset plus prosody/word length only, and onset plus prosody. Word properties were quantified to assess their influence on word recognition in the onset-only condition.

RESULTS

Word recognition speed was proportional to language experience. In the onset-only condition, only word frequency facilitated word recognition across groups. Addition of duration information or prosodic word form did not facilitate word recognition in bilingual individuals the way it did in monolingual individuals. For the bilingual groups, Spanish accent significantly facilitated recognition in the presence of prosodic information. Word attributes were far more consequential in the English accent than in the Spanish accent condition.

CONCLUSIONS

Word rhyme information, word properties, and accent affect gated word recognition differently in monolingual and bilingual individuals. Top-down strategies emanating from word properties that may facilitate single-word recognition are experience and context dependent and become less available in the presence of a nonnative accent.

Perseveration and Other Repetitive Verbal Behaviors: Functional Dissociations

This article will review types of perseveration from a neurolinguistic perspective. During the course of the article, continuous, stuck-in-set, and recurrent perseveration will be placed in contradistinction to several other types of repetitive behaviors commonly associated with neurogenic communication disorders. These include echolalia in mixed transcortical aphasia; conduite d'approche and conduite d'ecart in fluent aphasias; lexical and nonlexical automatisms in nonfluent aphasias; palilalia in neuromotor disorders, such as Parkinson's disease (PD); and sound, syllable, word, and phrase repetitions in neurogenic stuttering. When differentiating these phenomena from perseveration, it is helpful to consider the salient factors that condition observed behaviors in individual patients, such as overall speech fluency, inventory of available utterances, nature of eliciting tasks, and propositionality of responses. Information such as communication disorder diagnosis, underlying etiology, and known sites of lesion from each patient's total clinical profile may also assist with differentiation.

Prosody in apraxia of speech

Prosody is a complex process that involves modulation of pitch, loudness, duration, and linearity in the acoustic stream to serve linguistic and affective communication goals. It arises from the interaction of distributed neural networks that may be anatomically and functionally lateralized. Intrinsic prosody is mediated largely through left hemisphere mechanisms and encompasses those elements of linguistic microstructure (e.g., syllabic magnitudes and durations, basic consonantal and vocalic gesture specifications, and so) that yield the segmental aspects of speech. Extrinsic prosody is processed primarily by right hemisphere (RH) mechanisms and involves manipulation of intonation across longer perceptual groupings. Intrinsic prosody deficits can lead to several core symptoms of speech apraxia such as difficulty with utterance initiation and syllable transitionalization and may lead to the establishment of inappropriate syllable boundaries. The intrinsic prosody profiles associated with acquired apraxia of speech, developmental speech apraxia, and ataxic dysarthria may aid in the clinical differentiation of these disorders.

Timing and intensity variability in the metronomic speech of stuttering and nonstuttering speakers

The timing and intensity variability of 8 adults who stutter and 8 age-matched fluent speakers was investigated under metronomic conditions. Participants were required to produce double or triple-stress patterns at a slow speech rate (1 syllable/870 ms) when repeating the syllable /staet/or/straet/nine times. Measures that are sensitive to cyclic rather than overall variation in syllable timing and intensity were employed. Specifically, durational variation between successive syllable onsets as well as intensity variation of the beginning consonant and vowel in successive syllables were computed. Results revealed that, although intensity variation was similar, the timing of successive syllables of persons who stutter was significantly more variable than that of persons who do not stutter. These outcomes are discussed in relation to previous experiments of timing control of persons who stutter and normally fluent persons during metronomic stimulation.