The design of a project to assess bilateral versus unilateral hearing aid fitting

Binaural hearing provides advantages over monaural in several ways, particularly in difficult listening situations. For a person with bilateral hearing loss, the bilateral fitting of hearing aids thus seems like a natural choice. However, surprisingly few studies have been reported in which the additional benefit of bilateral versus unilateral hearing aid use has been investigated based on real-life experiences. Therefore, a project has been designed to address this issue and to find tools to identify people for whom the drawbacks would outweigh the advantages of bilateral fitting. A project following this design is likely to provide reliable evidence concerning differences in benefit between unilateral and bilateral fitting of hearing aids by evaluating correlations between entrance data and outcome measures and final preferences

Studies in electroencephalographic audiometry

This thesis investigates the application of steady state responses to averaged electroencephalographic audiometry (AEA). Steady state responses may be obtained using either amplitude modulated or frequency modulated stimulation. In both cases the stimulus variables are modulation frequency, modulation depth, carrier frequency and stimulus intensity. Other variables include the number of samples used to compile the average, the stimulus presentation (i.e. monaural or binaural), and the subject state (e.g. awake or under sedation). The effect of these parameters on the responses to both amplitude and frequency modulated stimulation has been investigated for normal hearing adults and children. For amplitude modulated stimulation the effect of modulation frequency exhibits a large degree of inter-subject variability, while the response behaviour as a function of the other parameters does not;. The optimal conditions for audiological assessment have been determined for all parameters with the exception of modulation frequency, which is a function of the individual. For frequency modulated stimulation, the inter-subject variability is small, and optimal conditions have been determined for all parameters. The steady state response thresholds to both amplitude and frequency modulated stimulation have been determined for adult and child clinical subjects. These thresholds were compared with the behavioural thresholds obtained using conventional audiometry. The responses to amplitude modulated stimulation may be obtained at 20 dB above behavioural threshold, and those to frequency modulated stimulation at 40 dB above behavioural threshold. Some of the relationships between the two forms of steady state response, the transient response, and the electroencephalogram have been investigated, and the advantages and disadvantages of the steady state responses as an audiological technique have been discussed

A Framework for Speechreading Acquisition Tools

At least 360 million people worldwide have disabling hearing loss that frequently causes difficulties in day-to-day conversations. Traditional technology (e.g., hearing aids) often fails to offer enough value, has low adoption rates, and can result in social stigma. Speechreading can dramatically improve conversational understanding, but speechreading is a skill that can be challenging to learn. To address this, we developed a novel speechreading acquisition framework that can be used to design Speechreading Acquisition Tools (SATs) – a new type of technology to improve speechreading acquisition. We interviewed seven speechreading tutors and used thematic analysis to identify and organise the key elements of our framework. We then evaluated our framework by using it to: 1) categorise every tutor-identified speechreading teaching technique, 2) critically evaluate existing conversational aids, and 3) design three new SATs. Through the use of SATs designed using our framework, the speechreading abilities of people with hearing loss around the world should be enhanced, thereby improving the conversational foundation of their day-to-day lives

The utility of magnetic resonance imaging in a trial to assess the effect of renal denervation in heart failure with preserved ejection fraction

Background Heart failure with preserved ejection fraction (HF-PEF) is common and has a poor prognosis with a 3 year mortality rate of 23%. There are currently no effective therapies for this condition. HF-PEF is characterized by symptoms of heart failure, normal or a mildly impaired ejection fraction and evidence of adverse cardiac and vascular remodelling. A feature of all heart failure is a heightened sympathetic nervous system (SNS), which can now be abrogated using renal denervation (RD). Methods We are conducting a study of patients with HF-PEF who will be randomised (2:1) to receive RD or open control. As a phase II mechanistic study we are primarily investigating the effect of RD on patient symptoms (questionnaire), cardio-pulmonary exercise function, B-type natriuretic peptide levels, left ventricular filling pressures, left ventricular mass and left atrial volume. We are also assessing macrovascular function using aorta imaging to calculate aorta distensibility, pulse wave velocity and aortic flow. Finally

Cardiovascular magnetic resonance predictors of heart failure in hypertrophic cardiomyopathy: the role of myocardial replacement fibrosis and the microcirculation

Introduction: Heart failure (HF) in hypertrophic cardiomyopathy (HCM) is associated with high morbidity and mortality. Predictors of HF, in particular the role of myocardial fibrosis and microvascular ischemia remain unclear. We assessed the predictive value of cardiovascular magnetic resonance (CMR) for development of HF in HCM in an observational cohort study. Methods: Serial patients with HCM underwent CMR, including adenosine first-pass perfusion, left atrial (LA) and left ventricular (LV) volumes indexed to body surface area (i) and late gadolinium enhancement (%LGE- as a % of total myocardial mass). We used a composite endpoint of HF death, cardiac transplantation, and progression to NYHA class III/IV. Results: A total of 543 patients with HCM underwent CMR, of whom 94 met the composite endpoint at baseline. The remaining 449 patients were followed for a median of 5.6 years. Thirty nine patients (8.7%) reached the composite endpoint of HF death (n = 7), cardiac transplantation (n = 2) and progression to NYHA class III/IV (n = 20). The annual incidence of HF was 2.0 per 100 person-years, 95% CI (1.6–2.6). Age, previous non-sustained ventricular tachycardia, LV end-systolic volume indexed to body surface area (LVESVI), LA volume index ; LV ejection fraction, %LGE and presence of mitral regurgitation were significant univariable predictors of HF, with LVESVI (Hazard ratio (HR) 1.44, 95% confidence interval (95% CI) 1.16–1.78, p = 0.001), %LGE per 10% (HR 1.44, 95%CI 1.14–1.82, p = 0.002) age (HR 1.37, 95% CI 1.06–1.77, p = 0.02) and mitral regurgitation (HR 2.6, p = 0.02) remaining independently predictive on multivariable analysis. The presence or extent of inducible perfusion defect assessed using a visual score did not predict outcome (p = 0.16, p = 0.27 respectively). Discussion: The annual incidence of HF in a contemporary ambulatory HCM population undergoing CMR is low. Myocardial fibrosis and LVESVI are strongly predictive of future HF, however CMR visual assessment of myocardial perfusion was not

Glasgow Hearing Aid Benefit Profile: Derivation and Validation of a Client-centered Outcome Measure for Hearing Aid Services

AbstractThe Glasgow Hearing Aid Benefit Profile (GHABP) has been derived, optimized, and verified as an instrument suitable for application in the context of the evaluation of the efficacy and effectiveness of rehabilitative services for hearing-impaired adults. The profile produces scales of preintervention disability, handicap, reported hearing aid use, reported benefit, satisfaction, and residual disability, obtained over a combination of prespecified listening circumstances and those nominated by individual hearing-impaired listeners. A validity criterion for the GHABP and other contenders for use in the evaluation of such services is proposed and justified. The outcome scales from the GHABP are demonstrated to exhibit the power to discriminate between hearing aid fittings, and the instrument is proposed as a suitable candidate for a routine service monitoring indicator as part of a program of quality assurance and standards. Abbreviations: GHABP = Glasgow Hearing Aid Benefit Profile, HDABI = Hearing Disability and Aid Benefit Interview, SII = Speech Intelligibility Index</jats:p