Audiology and Speech Pathology - Research Publications
Now showing items 1-12 of 186
Reducing Listening-Related Stress in School-Aged Children with Autism Spectrum Disorder
(SPRINGER/PLENUM PUBLISHERS, 2017-07-01)
High levels of stress and anxiety are common in children with Autism Spectrum Disorder (ASD). Within this study of school-aged children (20 male, 6 female) we hypothesised that functional hearing deficits (also pervasive in ASD) could be ameliorated by auditory interventions and that, as a consequence, stress levels would be reduced. The use of Ear-Level Remote Microphone devices and Classroom Amplification systems resulted in significantly improved listening, communication and social interaction and a reduction in physiologic stress levels (salivary cortisol) in both one-on-one and group listening situations.
Thermal damage threshold of neurons during infrared stimulation
(OSA - Optical Society of America, 2020-04-01)
In infrared neural stimulation (INS), laser-evoked thermal transients are used to generate small depolarising currents in neurons. The laser exposure poses a moderate risk of thermal damage to the target neuron. Indeed, exogenous methods of neural stimulation often place the target neurons under stressful non-physiological conditions, which can hinder ordinary neuronal function and hasten cell death. Therefore, quantifying the exposure-dependent probability of neuronal damage is essential for identifying safe operating limits of INS and other interventions for therapeutic and prosthetic use. Using patch-clamp recordings in isolated spiral ganglion neurons, we describe a method for determining the dose-dependent damage probabilities of individual neurons in response to both acute and cumulative infrared exposure parameters based on changes in injection current. The results identify a local thermal damage threshold at approximately 60 °C, which is in keeping with previous literature and supports the claim that damage during INS is a purely thermal phenomenon. In principle this method can be applied to any potentially injurious stimuli, allowing for the calculation of a wide range of dose-dependent neural damage probabilities. Unlike histological analyses, the technique is well-suited to quantifying gradual neuronal damage, and critical threshold behaviour is not required.
How Does Our Voice Change as We Age? A Systematic Review and Meta-Analysis of Acoustic and Perceptual Voice Data From Healthy Adults Over 50 Years of Age.
(American Speech-Language-Hearing Association, 2020-02-26)
Purpose Approximately 30% of adults over the age of 50 years present with altered vocal function. Our understanding of how these changes manifest acoustically and perceptually is derived from relatively modest-sized studies using a diversity of tools. Voice changes can arise from the onset of disease or disorder, but also age-related physiological changes, which may not reflect pathology as such. Here, we bring together data on acoustic, perceptual, and instrumental assessments (electroglottography), with the aim of gaining a better understanding of the changes occurring across these measurement domains. We consider these changes in the context of different acoustic features, software programs, and perceptual protocols. Method Studies of voice function in healthy older adults over the age of 50 years were sought. Literature was systematically searched with 746 abstracts reviewed. Forty-seven studies were included in the review. A meta-analysis of included studies compared voice acoustic parameters between sex and age. Sixteen acoustic parameters collected from 1,475 participants were analyzed in the meta-analysis. These included some previously unpublished analyses using data provided by authors of included studies. Results Data from the systematic review suggest that older individuals are perceived to present with higher overall scores of dysphonia and roughness, breathiness, strain, and instability. Acoustically, males have significantly higher scores on measures of perturbation, including noise-to-harmonic ratio and absolute jitter. The meta-analysis outcomes suggest that participants aged 80-89 years produce significantly higher fundamental frequency, jitter percent, shimmer percent, and shimmer in decibels compared to participants aged 60-69 years and a significant increase in relative average perturbation, jitter percent, and shimmer in decibels compared to participants aged 70-79 years. Limited data were available comparing acoustic measures using the same acoustic software. Conclusions Variations in fundamental frequency and frequency and amplitude perturbation increase as healthy adults age. It was difficult to draw definitive conclusions based on existing literature due to variability in hardware used, limited descriptions of study cohorts, or missing data from statistical analysis.
Improving outcomes of preschool language delay in the community: protocol for the Language for Learning randomised controlled trial
BACKGROUND: Early language delay is a high-prevalence condition of concern to parents and professionals. It may result in lifelong deficits not only in language function, but also in social, emotional/behavioural, academic and economic well-being. Such delays can lead to considerable costs to the individual, the family and to society more widely. The Language for Learning trial tests a population-based intervention in 4 year olds with measured language delay, to determine (1) if it improves language and associated outcomes at ages 5 and 6 years and (2) its cost-effectiveness for families and the health care system. METHODS/DESIGN: A large-scale randomised trial of a year-long intervention targeting preschoolers with language delay, nested within a well-documented, prospective, population-based cohort of 1464 children in Melbourne, Australia. All children received a 1.25-1.5 hour formal language assessment at their 4th birthday. The 200 children with expressive and/or receptive language scores more than 1.25 standard deviations below the mean were randomised into intervention or 'usual care' control arms. The 20-session intervention program comprises 18 one-hour home-based therapeutic sessions in three 6-week blocks, an outcome assessment, and a final feed-back/forward planning session. The therapy utilises a 'step up-step down' therapeutic approach depending on the child's language profile, severity and progress, with standardised, manualised activities covering the four language development domains of: vocabulary and grammar; narrative skills; comprehension monitoring; and phonological awareness/pre-literacy skills. Blinded follow-up assessments at ages 5 and 6 years measure the primary outcome of receptive and expressive language, and secondary outcomes of vocabulary, narrative, and phonological skills. DISCUSSION: A key strength of this robust study is the implementation of a therapeutic framework that provides a standardised yet tailored approach for each child, with a focus on specific language domains known to be associated with later language and literacy. The trial responds to identified evidence gaps, has outcomes of direct relevance to families and the community, includes a well-developed economic analysis, and has the potential to improve long-term consequences of early language delay within a public health framework. TRIAL REGISTRATION: Current Controlled Trials ISRCTN03981121.
Quantifying ultrasonic mouse vocalizations using acoustic analysis in a supervised statistical machine learning framework
(NATURE PUBLISHING GROUP, 2019-05-30)
Examination of rodent vocalizations in experimental conditions can yield valuable insights into how disease manifests and progresses over time. It can also be used as an index of social interest, motivation, emotional development or motor function depending on the animal model under investigation. Most mouse communication is produced in ultrasonic frequencies beyond human hearing. These ultrasonic vocalizations (USV) are typically described and evaluated using expert defined classification of the spectrographic appearance or simplistic acoustic metrics resulting in nine call types. In this study, we aimed to replicate the standard expert-defined call types of communicative vocal behavior in mice by using acoustic analysis to characterize USVs and a principled supervised learning setup. We used four feature selection algorithms to select parsimonious subsets with maximum predictive accuracy, which are then presented into support vector machines (SVM) and random forests (RF). We assessed the resulting models using 10-fold cross-validation with 100 repetitions for statistical confidence and found that a parsimonious subset of 8 acoustic measures presented to RF led to 85% correct out-of-sample classification, replicating the experts' labels. Acoustic measures can be used by labs to describe USVs and compare data between groups, and provide insight into vocal-behavioral patterns of mice by automating the process on matching the experts' call types.
Organotypic Cocultures of Human Pluripotent Stem Cell Derived-Neurons with Mammalian Inner Ear Hair Cells and Cochlear Nucleus Slices
(Hindawi Limited, 2019-11-20)
Stem cells have been touted as a source of potential replacement neurons for inner ear degeneration for almost two decades now; yet to date, there are few studies describing the use of human pluripotent stem cells (hPSCs) for this purpose. If stem cell therapies are to be used clinically, it is critical to validate the usefulness of hPSC lines in vitro and in vivo. Here, we present the first quantitative evidence that differentiated hPSC-derived neurons that innervate both the inner ear hair cells and cochlear nucleus neurons in coculture, with significantly more new synaptic contacts formed on target cell types. Nascent contacts between stem cells and hair cells were immunopositive for both synapsin I and VGLUT1, closely resembling expression of these puncta in endogenous postnatal auditory neurons and control cocultures. When hPSCs were cocultured with cochlear nucleus brainstem slice, significantly greater numbers of VGLUT1 puncta were observed in comparison to slice alone. New VGLUT1 puncta in cocultures with cochlear nucleus slice were not significantly different in size, only in quantity. This experimentation describes new coculture models for assessing auditory regeneration using well-characterised hPSC-derived neurons and highlights useful methods to quantify the extent of innervation on different cell types in the inner ear and brainstem.
Treatment for speech disorder in Friedreich ataxia and other
hereditary ataxia syndromes (Review)
(JohnWiley & Sons, Ltd, 2014-12-01)
Background: Hereditary ataxia syndromes can result in significant speech impairment, a symptom thought to be responsive to treatment. The type of speech impairment most commonly reported in hereditary ataxias is dysarthria. Dysarthria is a collective term referring to a group of movement disorders affecting the muscular control of speech. Dysarthria affects the ability of individuals to communicate and to participate in society. This in turn reduces quality of life. Given the harmful impact of speech disorder on a person’s functioning, treatment of speech impairment in these conditions is important and evidence-based interventions are needed. Objectives: To assess the effects of interventions for speech disorder in adults and children with Friedreich ataxia and other hereditary ataxias. Search methods: On 14 October 2013, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, EMBASE, CINAHL Plus, PsycINFO, Education Resources Information Center (ERIC), Linguistics and Language Behavior Abstracts (LLBA), Dissertation Abstracts and trials registries.We checked all references in the identified trials to identify any additional published data. Selection criteria: We considered for inclusion randomised controlled trials (RCTs) or quasi-RCTs that compared treatments for hereditary ataxias with no treatment, placebo or another treatment or combination of treatments, where investigators measured speech production. Data collection and analysis: Two review authors independently selected trials for inclusion, extracted data and assessed the risk of bias of included studies using the standard methodological procedures expected by The Cochrane Collaboration. The review authors collected information on adverse effects from included studies.We did not conduct a meta-analysis as no two studies utilised the same assessment procedures within the same treatment. Main results: Fourteen clinical trials, involving 721 participants, met the criteria for inclusion in the review. Thirteen studies compared a pharmaceutical treatment with placebo (or a low dose of the intervention), in heterogenous groups of degenerative cerebellar ataxias. Three compounds were studied in two trials each: a levorotatory formof 5-hydroxytryptophan (L-5HT), idebenone and thyrotropin-releasing hormone tartrate (TRH-T); each of the other compounds (riluzole, varenicline, buspirone, betamethasone, coenzyme Q10 with vitamin E, _-tocopheryl quinone and erythropoietin) were studied in one trial. The 14th trial, involving a mixed group of participants with spinocerebellar ataxia, compared the effectiveness of nonspecific physiotherapy and occupational therapy within an inpatient hospital setting to no treatment. No studies utilised traditional speech therapies. We defined the primary outcome measure in this review as the percentage change (improvement) in overall speech production immediately following completion of the intervention or later, measured by any validated speech assessment tool. None of the trials included speech as a primary outcome or examined speech using any validated speech assessment tool. Eleven studies reported speech outcomes derived from a subscale embedded within disease rating scales. The remaining three studies used alternative assessments tomeasure speech, including mean time to produce a standard sentence, a subjective rating of speech on a 14-point analogue scale, patient-reported assessment of the impact of dysarthria on activities of daily living and acoustic measures of syllable length. One study measured speech both subjectively as part of a disease rating scale and with further measures of speech timing. Three studies utilised the Short Form-36 Health Survey (SF-36) and one used the Child Health Questionnaire as measures of general quality of life. A further study utilised the Functional Independence Measure to assess functional health. Five studies reported statistically significant improvement on an overall disease rating scale in which a speech subscale was included. Only three of those studies provided specific data on speech performance; all were comparisons with placebo. Improvements in overall disease severity were observed with _-tocopheryl quinone; however, no significant changes were found on the speech subscale in a group of individuals with Friedreich ataxia. A statistically significant improvement in speech according to a speech disorders subscale was observed with betamethasone. Riluzole was found to have a statistically significant effect on speech in a group of participants with mixed hereditary, sporadic and unknown origin ataxias. No significant differences were observed between treatment and placebo in any other pharmaceutical study. A statistically significant improvement in functional independence occurred at the end of the treatment period in the rehabilitation study compared to the delayed treatment group but these effects were not present 12 to 24 weeks after treatment. Of the four studies that assessed quality of life, none found a significant effect. A variety of minor adverse events were reported for the 13 pharmaceutical therapies, including gastrointestinal side effects and nausea. Serious adverse effects were reported in two participants in one of the L-5HT trials (participants discontinued due to gastrointestinal effects), and in four participants (three taking idebenone, one taking placebo) in the idebenone studies. Serious adverse events with idebenone were gastrointestinal side effects and, in people with a previous history of these events, chest pain and idiopathic thrombocytopenic purpura. The rehabilitation study did not report any adverse events. We considered six studies to be at high risk of bias in some respect. We suspected inadequate blinding of participants or assessors in four studies and poor randomisation in a further two studies. There was a high risk of reporting bias in two studies and attrition bias in four studies. Only one study had a low risk of bias across all criteria. Taken together with other limitations of the studies relating to the validity of the measurement scales used, we downgraded the quality of the evidence for many of the outcomes to low or very low. Authors’ conclusions There is insufficient and low or very low quality evidence from either RCTs or observational studies to determine the effectiveness of any treatment for speech disorder in any of the hereditary ataxia syndromes.
Treatment for speech disorder in Friedreich ataxia and other hereditary ataxia syndromes (Protocol)
(John Wiley & Sons, Ltd, 2011)
This is the protocol for a review and there is no abstract. The objectives are as follows:To assess the effects of interventions for speech impairment in people with Friedreich ataxia and other hereditary ataxias.
Motor speech and non-motor language endophenotypes of Parkinson's disease
(Taylor & Francis, 2019)
Introduction: Idiopathic Parkinson's Disease (PD) results in a range of motor and non-motor impairments. Clinical diagnosis commonly occurs after substantial neurophysiological damage limiting the opportunity for neuroprotective treatments. Uncovering sensitive objective markers with the capacity to detect pre-symptomatic disease and track disease progression is therefore a priority. Speech may provide an ideal proxy marker for PD; a quantifiable biometric that displays salient changes in early disease and appears to evolve with disease progression. Areas covered: This review describes the endophenotype of speech, voice, cognition and language modalities in PD and investigates the speech as a 'proxy marker' of PD disease state. Expert opinion: Detailed characterization at different disease stages are needed and must incorporate longitudinal assessment to capture small but significant changes in speech, voice, cognition and language modalities within patient changes over time. Advances in technology are leading to new opportunities for acquiring data remotely and more frequently, offering more ecologically valid testing environments. Combined with automated signal processing and analysis, symptoms may also be tracked in-home readily. Features extracted may provide a 'proxy marker' for early identification of PD and objective monitoring of disease progression.
Language-General Auditory-Visual Speech Perception: Thai-English and Japanese-English McGurk Effects.
Cross-language McGurk Effects are used to investigate the locus of auditory-visual speech integration. Experiment 1 uses the fact that , as in 'sing', is phonotactically legal in word-final position in English and Thai, but in word-initial position only in Thai. English and Thai language participants were tested for 'n' perception from auditory [m]/visual  (A[m]V) in word-initial and -final positions. Despite English speakers' native language bias to label word-initial  as 'n', the incidence of 'n' percepts to A[m]V was equivalent for English and Thai speakers in final and initial positions. Experiment 2 used the facts that (i) [ð] as in 'that' is not present in Japanese, and (ii) English speakers respond more often with 'tha' than 'da' to A[ba]V[ga], but more often with 'di' than 'thi' to A[bi]V[gi]. English and three groups of Japanese language participants (Beginner, Intermediate, Advanced English knowledge) were presented with A[ba]V[ga] and A[bi]V[gi] by an English (Experiment 2a) or a Japanese (Experiment 2b) speaker. Despite Japanese participants' native language bias to perceive 'd' more often than 'th', the four groups showed a similar phonetic level effect of [a]/[i] vowel context × 'th' vs. 'd' responses to A[b]V[g] presentations. In Experiment 2b this phonetic level interaction held, but was more one-sided as very few 'th' responses were evident, even in Australian English participants. Results are discussed in terms of a phonetic plus postcategorical model, in which incoming auditory and visual information is integrated at a phonetic level, after which there are post-categorical phonemic influences.
Auditory neuropathy in a patient with hemochromatosis.
(Elsevier BV, 2016-12)
Objective: To evaluate the auditory function of an individual with genetically confirmed hemochromatosis. Methods: A 57 year old male with mildly impaired sound detection thresholds underwent a range of behavioural, electroacoustic and electrophysiologic assessments. These included the recording of otoacoustic emissions and auditory brainstem responses, measurement of monaural temporal resolution and evaluation of binaural speech processing. Findings for this patient were subsequently compared with those of 80 healthy controls with similar audiometric thresholds. Results: The patient showed the three cardinal features of auditory neuropathy, presenting with evidence of normal cochlear outer hair cell function, disrupted neural activity in the auditory nerve/brainstem and impaired temporal processing. His functional hearing ability (speech perception) was significantly affected and suggested a reduced capacity to use localization cues to segregate signals in the presence of background noise. Conclusion: We present the first case of an individual with hemochromatosis and auditory neuropathy. The findings for this patient highlight the need for careful evaluation of auditory function in individuals with the disorder.