27 research outputs found

    The Effect of Formant Measurement Methods on Vowel Space in Patients with Parkinson\u27s Disease Before and After Voice Treatment

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    LSVT-LOUD® has been shown to improve phonatory quality in patients with PD. Previous studies have shown an increase in vowel space area following treatment, but questions remain regarding possible methodological issues in interaction with phonatory factors. This study addresses these questions by comparing multiple formant measurment methods and vowel space metrics. Ten participants were recorded on two separate days before and after treatment. Formants were measured using a human-guided reference (dubbed \u27HGIM\u27), LPC, and two forms of cepstrally-liftered spectrum. Multiple vowel space metrics including the vowel articulation index, F2i/F2u, area of the vowel quadrilateral, and vowel formant dispersion utilized both lax and corner vowels to explore vowel space changes. Analysis revealed no significant change in vowel space following LSVT. High variability in LPC with a fixed coefficient was noted. These results do not support previous claims of increased vowel space but suggest that formant measurement methods may influence results

    Development of Markerless Systems for Automatic Analysis of Movements and Facial Expressions: Applications in Neurophysiology

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    This project is focused on the development of markerless methods for studying facial expressions and movements in neurology, focusing on Parkinson’s disease (PD) and disorders of consciousness (DOC). PD is a neurodegenerative illness that affects around 2% of the population over 65 years old. Impairments of voice/speech are among the main signs of PD. This set of impairments is called hypokinetic dysarthria, because of the reduced range of movements involved in speech. This reduction can be visible also in other facial muscles, leading to a hypomimia. Despite the high percentage of patients that suffer from dysarthria and hypomimia, only a few of them undergo speech therapy with the aim to improve the dynamic of articulatory/facial movements. The main reason is the lack of low cost methodologies that could be implemented at home. DOC after coma are Vegetative State (VS), characterized by the absence of self-awareness and awareness of the environment, and Minimally Conscious State (MCS), in which certain behaviors are sufficiently reproducible to be distinguished from reflex responses. The differential diagnosis between VS and MCS can be hard and prone to a high rate of misdiagnosis (~40%). This differential diagnosis is mainly based on neuro-behavioral scales. A key role to plan the rehabilitation in DOC patients is played by the first diagnosis after coma. In fact, MCS patients are more prone to a consciousness recovery than VS patients. Concerning PD the aim is the development of contactless systems that could be used to study symptoms related to speech and facial movements/expressions. The methods proposed here, based on acoustical analysis and video processing techniques could support patients during speech therapy also at home. Concerning DOC patients the project is focused on the assessment of reflex and cognitive responses to standardized stimuli. This would allow objectifying the perceptual analysis performed by clinicians

    Models and Analysis of Vocal Emissions for Biomedical Applications

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    The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies

    Models and Analysis of Vocal Emissions for Biomedical Applications

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    The MAVEBA Workshop proceedings, held on a biannual basis, collect the scientific papers presented both as oral and poster contributions, during the conference. The main subjects are: development of theoretical and mechanical models as an aid to the study of main phonatory dysfunctions, as well as the biomedical engineering methods for the analysis of voice signals and images, as a support to clinical diagnosis and classification of vocal pathologies

    Models and Analysis of Vocal Emissions for Biomedical Applications

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    The International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA) came into being in 1999 from the particularly felt need of sharing know-how, objectives and results between areas that until then seemed quite distinct such as bioengineering, medicine and singing. MAVEBA deals with all aspects concerning the study of the human voice with applications ranging from the neonate to the adult and elderly. Over the years the initial issues have grown and spread also in other aspects of research such as occupational voice disorders, neurology, rehabilitation, image and video analysis. MAVEBA takes place every two years always in Firenze, Italy

    ACOUSTIC SPEECH MARKERS FOR TRACKING CHANGES IN HYPOKINETIC DYSARTHRIA ASSOCIATED WITH PARKINSON’S DISEASE

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    Previous research has identified certain overarching features of hypokinetic dysarthria associated with Parkinson’s Disease and found it manifests differently between individuals. Acoustic analysis has often been used to find correlates of perceptual features for differential diagnosis. However, acoustic parameters that are robust for differential diagnosis may not be sensitive to tracking speech changes. Previous longitudinal studies have had limited sample sizes or variable lengths between data collection. This study focused on using acoustic correlates of perceptual features to identify acoustic markers able to track speech changes in people with Parkinson’s Disease (PwPD) over six months. The thesis presents how this study has addressed limitations of previous studies to make a novel contribution to current knowledge. Speech data was collected from 63 PwPD and 47 control speakers using an online podcast software at two time points, six months apart (T1 and T2). Recordings of a standard reading passage, minimal pairs, sustained phonation, and spontaneous speech were collected. Perceptual severity ratings were given by two speech and language therapists for T1 and T2, and acoustic parameters of voice, articulation and prosody were investigated. Two analyses were conducted: a) to identify which acoustic parameters can track perceptual speech changes over time and b) to identify which acoustic parameters can track changes in speech intelligibility over time. An additional attempt was made to identify if these parameters showed group differences for differential diagnosis between PwPD and control speakers at T1 and T2. Results showed that specific acoustic parameters in voice quality, articulation and prosody could differentiate between PwPD and controls, or detect speech changes between T1 and T2, but not both factors. However, specific acoustic parameters within articulation could detect significant group and speech change differences across T1 and T2. The thesis discusses these results, their implications, and the potential for future studies

    Models and analysis of vocal emissions for biomedical applications

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    This book of Proceedings collects the papers presented at the 4th International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2005, held 29-31 October 2005, Firenze, Italy. The workshop is organised every two years, and aims to stimulate contacts between specialists active in research and industrial developments, in the area of voice analysis for biomedical applications. The scope of the Workshop includes all aspects of voice modelling and analysis, ranging from fundamental research to all kinds of biomedical applications and related established and advanced technologies

    Models and Analysis of Vocal Emissions for Biomedical Applications

    Get PDF
    The Models and Analysis of Vocal Emissions with Biomedical Applications (MAVEBA) workshop came into being in 1999 from the particularly felt need of sharing know-how, objectives and results between areas that until then seemed quite distinct such as bioengineering, medicine and singing. MAVEBA deals with all aspects concerning the study of the human voice with applications ranging from the neonate to the adult and elderly. Over the years the initial issues have grown and spread also in other aspects of research such as occupational voice disorders, neurology, rehabilitation, image and video analysis. MAVEBA takes place every two years always in Firenze, Italy

    Changes in speech intelligibility and acoustic distinctiveness along a speech rate continuum in Parkinson’s disease

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    Asking a person to speak slowly is a common technique in speech therapy for people with Parkinson’s disease (PD). Slowed speaking rates are thought to bring about changes in speech production that make it easier for people with speech impairments associated with PD to be understood, but this is not always the case. Furthermore, research suggests that using faster speech does not necessarily lead to decreases in speech intelligibility for some people with PD. Most studies of rate modification in PD have only included one or two rate adjustments to investigate the relationship between speech rate, intelligibility, and acoustic aspects of speech production. The present study adds to this literature and expands it by eliciting a broader range of speech rates than has previously been studied in order to provide a comprehensive description of changes along such a continuum. Two groups of people with PD and documented speech changes participated: 22 receiving standard pharmaceutical intervention, and 12 who additionally had undergone deep brain stimulation surgery (DBS), a common surgical treatment for PD. DBS is often associated with further speech impairment, but it is unknown to what extent these individuals may benefit from speech rate adjustments. Younger and older healthy control groups were also included. All participants were asked to modify their speech rate along a seven-step continuum from very slow to very fast while reading words, sentences, and responding to prompts. Naïve listeners later heard these speech samples and were asked to either transcribe or rate what they heard. Results indicated different patterns of speech changes across groups, rates, and tasks. Sentence reading and conversational speech were rated as being more intelligible at slow rates, and less intelligible at fast rates. All modified rates were found to negatively impact speech sound identification during a novel carrier phrase task. Slower speech was overall associated with greater acoustic contrast and variability, lower intensity, and higher voice quality. Differences in acoustic speech adjustments across the groups and speech rates emerged, however, in particular for the DBS group. Findings pointed to a complex relationship between speech rate modifications, acoustic distinctiveness, and intelligibility
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