Do Acoustic Characteristics of Dysarthria in People With Parkinson's Disease Differ Across Languages?

PURPOSE: Cross-language studies suggest more similarities than differences in how dysarthria affects the speech of people with Parkinson's disease (PwPD) who speak different languages. In this study, we aimed to identify the relative contribution of acoustic variables to distinguish PwPD from controls who spoke varieties of two Romance languages, French and Portuguese. METHOD: This bi-national, cross-sectional, and case-controlled study included 129 PwPD and 124 healthy controls who spoke French or Portuguese. All participants underwent the same clinical examinations, voice/speech recordings, and self-assessment questionnaires. PwPD were evaluated off and on optimal medication. Inferential analyses included Disease (controls vs. PwPD) and Language (French vs. Portuguese) as factors, and random decision forest algorithms identified relevant acoustic variables able to distinguish participants: (a) by language (French vs. Portuguese) and (b) by clinical status (PwPD on and off medication vs. controls). RESULTS: French-speaking and Portuguese-speaking individuals were distinguished from each other with over 90% accuracy by five acoustic variables (the mean fundamental frequency and the shimmer of the sustained vowel /a/ production, the oral diadochokinesis performance index, the relative sound level pressure and the relative sound pressure level standard deviation of the text reading). A distinct set of parameters discriminated between controls and PwPD: for men, maximum phonation time and the oral diadochokinesis speech proportion were the most significant variables; for women, variables calculated from the oral diadochokinesis were the most discriminative. CONCLUSIONS: Acoustic variables related to phonation and voice quality distinguished between speakers of the two languages. Variables related to pneumophonic coordination and articulation rate were the more effective in distinguishing PwPD from controls. Thus, our research findings support that respiration and diadochokinesis tasks appear to be the most appropriate to pinpoint signs of dysarthria, which are largely homogeneous and language-universal. In contrast, identifying language-specific variables with the speech tasks and acoustic variables studied was less conclusive.

The contribution of visual articulatory gestures and orthography to speech processing: Evidence from novel word learning.

Auditory speech appears to be linked to visual articulatory gestures and orthography through different mechanisms. Yet, both types of visual information have a strong influence on speech processing. The present study directly compared their contributions to speech processing using a novel word learning paradigm. Native speakers of French, who were familiar with English, learned minimal pairs of novel English words containing the English /θ/-/f/ phonemic contrast under one of three exposure conditions: (a) the auditory forms of novel words alone, (b) the auditory forms associated with articulatory gestures, or (c) the auditory forms associated with orthography. The benefits of the three methods were compared during training and at two posttraining time points where the visual cues were no longer available. We also assessed participants' auditory-only discrimination of the /θ/-/f/ contrast pretraining and posttraining. During training, the visual cues facilitated novel word learning beyond the benefit of the auditory input alone. However, these additional benefits did not persist when participants' discrimination and novel word learning performance were assessed immediately after training. Most interestingly, after a night's sleep, participants who were exposed to orthography during training showed significant improvement in both discrimination and novel word learning compared to the previous day. The findings are discussed in terms of online versus residual impacts of articulatory gestures and orthography on speech processing. While both visual cues are beneficial when they are simultaneously presented with speech, only orthography shows residual impacts leading to a sleep-dependent enhancement of lexical knowledge through memory consolidation and retuning of the second language /θ/-/f/ contrast. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Orthography and second language word learning: Moving beyond "friend or foe?"

French participants learned English pseudowords either with the orthographic form displayed under the corresponding picture (Audio-Ortho) or without (Audio). In a naming task, pseudowords learned in the Audio-Ortho condition were produced faster and with fewer errors, providing a first piece of evidence that orthographic information facilitates the learning and on-line retrieval of productive vocabulary in a second language. Formant analyses, however, showed that productions from the Audio-Ortho condition were more French-like (i.e., less target-like), a result confirmed by a vowel categorization task performed by native speakers of English. It is argued that novel word learning and pronunciation accuracy should be considered together.

Dysarthria in individuals with Parkinson's disease: a protocol for a binational, cross-sectional, case-controlled study in French and European Portuguese (FraLusoPark).

INTRODUCTION: Individuals with Parkinson's disease (PD) have to deal with several aspects of voice and speech decline and thus alteration of communication ability during the course of the disease. Among these communication impairments, 3 major challenges include: (1) dysarthria, consisting of orofacial motor dysfunction and dysprosody, which is linked to the neurodegenerative processes; (2) effects of the pharmacological treatment, which vary according to the disease stage; and (3) particular speech modifications that may be language-specific, that is, dependent on the language spoken by the patients. The main objective of the FraLusoPark project is to provide a thorough evaluation of changes in PD speech as a result of pharmacological treatment and disease duration in 2 different languages (French vs European Portuguese). METHODS AND ANALYSIS: Individuals with PD are enrolled in the study in France (N=60) and Portugal (N=60). Their global motor disability and orofacial motor functions is assessed with specific clinical rating scales, without (OFF) and with (ON) pharmacological treatment. 2 groups of 60 healthy age-matched volunteers provide the reference for between-group comparisons. Along with the clinical examinations, several speech tasks are recorded to obtain acoustic and perceptual measures. Patient-reported outcome measures are used to assess the psychosocial impact of dysarthria on quality of life. ETHICS AND DISSEMINATION: The study has been approved by the local responsible committees on human experimentation and is conducted in accordance with the ethical standards. A valuable large-scale database of speech recordings and metadata from patients with PD in France and Portugal will be constructed. Results will be disseminated in several articles in peer-reviewed journals and in conference presentations. Recommendations on how to assess speech and voice disorders in individuals with PD to monitor the progression and management of symptoms will be provided. TRIAL REGISTRATION NUMBER: NCT02753192, Pre-results.

An intonational cue to word segmentation in phonemically identical sequences.

We investigated the use of language-specific intonational cues to word segmentation in French. Participants listened to phonemically identical sequences such as /selafi/, C'est la fiche/l'affiche "It's the sheet/poster." We modified the f0 of the first vowel /a/ of the natural consonant-initial production la fiche, so that it was equal to that of the natural vowel-initial production l'affiche (resynth-consonant-equal condition), higher (resynth-consonant-higher condition), or lower (resynth-consonant-lower condition). In a two-alternative forced choice task (Experiment 1), increasing the f0 in the /a/ of la fiche increased the percentage of vowel-initial (affiche) responses. In Experiment 2, participants made visual lexical decisions to vowel-initial targets (affiche) following both the natural consonant-initial production (la fiche) and the resynth-consonant-equal version. Facilitation was found only for the resynth-consonant-equal condition, suggesting that raising the f0 allowed online activation of vowel-initial targets. The recognition system seems to exploit intonational information to guide segmentation toward the beginning of content words.

Effects of pitch accent position, type, and status on focus projection.

This paper examines predictions made by two theories of the relationship between pitch accent and focus. The empirical evidence presented suggests that listeners are sensitive to a variety of factors that may affect the focus projection ability of pitch accents, that is the ability of a pitch accent on one word to mark focus on a larger constituent. The findings suggest that listeners' interpretation of focus structure is most sensitive to the presence or absence of a pitch accent on a focused constituent and the deaccenting of following unfocused material (pitch accent position). Preliminary evidence suggests that the status of a pitch accent as nuclear or prenuclear may also affect listeners' interpretations, though to a lesser extent than accent position. Finally, the results show that focus projection is affected only minimally, if at all, by the type of pitch accent (at least for the two accent types compared (H* vs. L + H*)).