Dysarthria

About: Dysarthria is a research topic. Over the lifetime, 2402 publications have been published within this topic receiving 56554 citations.

Prosodic feature extraction for assessment and treatment of dysarthria

Abstract: Dysarthria, a neurological motor speech disorder caused by lesions to the central and peripheral nervous system, accounts for over 40% of neurological disorders referred to pathologists in 2013[1]. This affects the ability of speakers to control the movement of speech production muscles due to muscle weakness. Dysarthria is characterised by reduced loudness, high pitch variability, monotonous speech, poor voice quality and reduced intelligibility [2]. Current techniques for dysarthria assessment are based on perception, which do not give objective measurements for the severity of this speech disorder. There is therefore a need to explore objective techniques for dysarthria assessment and treatment. The goal of this research is to identify and extract the main acoustic features which can be used to describe the type and severity of this disorder. An acoustic feature extraction and classification technique is proposed in this work. The proposed method involves a pre-processing stage where audio samples are filtered to remove noise and resampled at 8 kHz. The next stage is a feature extraction stage where pitch, intensity, formants, zero-crossing rate, speech rate and cepstral coefficients are extracted from the speech samples. Classification of the extracted features is carried out using a single layer neural network. After the classification, a treatment tool is to be developed to assist patients, through tailored exercises, to improve their articulatory ability, intelligibility, intonation and voice quality. Consequently, this proposed technique will assist speech therapists in tracking the progress of patients over time. It will also provide an acoustic objective measurement for dysarthria severity assessment. Some of the potential applications of this technology include management of cognitive speech impairments, treatment of speech difficulties in children and other advanced speech and language applications.

How expertise and language familiarity influence perception of speech of people with Parkinson's disease.

Abstract: Parkinson's disease (PD) is a progressive neurological disorder characterized by several motor and non-motor manifestations. PD frequently leads to hypokinetic dysarthria, which affects speech production and often has a detrimental impact on everyday communication. Among the typical manifestations of hypokinetic dysarthria, speech and language therapists (SLTs) identify prosody as the most affected cluster of speech characteristics. However, less is known about how untrained listeners perceive PD speech and how affected prosody influences their assessments of speech. This study explores the perception of sentence type intonation and healthiness of PD speech by listeners with different levels of familiarity with speech disorders in Dutch. We investigated assessments and classification accuracy differences between Dutch-speaking SLTs (n = 18) and Dutch/non-Dutch speaking untrained listeners (n = 27 and n = 124, respectively). We collected speech data from 30 Dutch speakers diagnosed with PD and 30 Dutch healthy controls. The stimuli set consisted of short phrases from spontaneous and read speech and of phrases produced with different sentence type intonation. Listeners participated in an online experiment targeting classification of sentence type intonation and perceived healthiness of speech. Results indicate that both familiarity with speech disorders and with speakers' language are significant and have different effects depending on the task type, as different listener groups demonstrate different classification accuracy. There is evidence that untrained Dutch listeners classify PD speech as unhealthy more accurately than both trained Dutch and untrained non-Dutch listeners, while trained Dutch listeners outperform the other two groups in sentence type classification.

Transcranial direct current stimulation over the primary motor cortex improves speech production in post-stroke dysarthric speakers: A randomized pilot study

Abstract: Purpose The current study investigated the therapeutic potential of transcranial direct current stimulation (tDCS) on speech intelligibility, speech-related physiological and vocal functions among post-stroke dysarthric patients. Method Nine chronic post-stroke dysarthric patients were randomly assigned to the stimulation or sham group. The stimulation group received 2mA of anodal tDCS over the left inferior primary motor cortex for 15 minutes, while the sham group received 30s of stimulation under the same settings. All the participants received 10 daily 15 minutes of individualized speech therapy targeting their dominant phonological process or phonemes with the greatest difficulty. The outcome measures included (1) perceptual analysis of single words, passage reading and diadochokinetic rate, (2) acoustic analysis of a sustained vowel, and (3) kinematic analysis of rapid syllable repetitions and syllable production in sentence, conducted before and after the treatment. Results The results revealed that both the stimulation and sham groups had improved perceptual speech intelligibility at the word level, reduced short rushes of speech during passage reading, improved rate during alternating motion rate, AMR-kha1, and improved articulatory kinematics in AMR-tha1 and syllables /tha1/ and /kha1/ production in sentence. Compared to the sham group, the stimulation group showed significant improvement in articulatory kinematics in AMR-kha1 and syllable /kha1/ production in sentence. The findings also showed that anodal stimulation led to reduced shimmer value in sustained vowel /a/ phonation, positive changes in articulatory kinematics in AMR-tha1 and syllables /pha1/ and /kha1/ production in sentence at the post treatment measure. In addition to positive effects on articulatory control, reduced perturbation of voice amplitude documented in the stimulation group post treatment suggests possible tDCS effects on the vocal function. Conclusions The current study documented the beneficial effects of anodal tDCS over the primary motor cortex on speech production and suggested that combined tDCS and speech therapy may promote recovery from post-stroke dysarthria.