Randomised controlled feasibility trial of an active communication education programme plus hearing aid provision versus hearing aid provision alone (ACE To HEAR).

OBJECTIVE: To establish the acceptability and feasibility of delivering the Active Communication Education (ACE) programme to increase quality of life through improving communication and hearing aid use in the UK National Health Service. DESIGN: Randomised controlled, open feasibility trial with embedded economic and process evaluations. SETTING: Audiology departments in two hospitals in two UK cities. PARTICIPANTS: Twelve hearing aid users aged 18 years or over who reported moderate or less than moderate benefit from their new hearing aid. INTERVENTIONS: Consenting participants (along with a significant other) were to be randomised by a remote, centralised randomisation service in groups to ACE plus treatment-as-usual (intervention group) or treatment-as-usual only (control group). PRIMARY OUTCOME MEASURES: The primary outcomes were related to feasibility: recruitment, retention, treatment adherence and acceptability to participants and fidelity of treatment delivery. SECONDARY OUTCOME MEASURES: International Outcomes Inventory for Hearing Aids, Self-Assessment of Communication, EQ-5D-5L and Short-Form 36. Blinding of the participants and facilitator was not possible. RESULTS: Twelve hearing aid users and six significant others consented to take part. Eight hearing aid users were randomised: four to the intervention group; and four to treatment-as-usual only. Four significant others participated alongside the randomised participants. Recruitment to the study was very low and centres only screened 466 hearing aid users over the 15-month recruitment period, compared with the approximately 3500 anticipated. Only one ACE group and one control group were formed. ACE could be delivered and appeared acceptable to participants. We were unable to robustly assess attrition and attendance rates due to the low sample size. CONCLUSIONS: While ACE appeared acceptable to hearing aid users and feasible to deliver, it was not feasible to identify and recruit participants struggling with their hearing aids at the 3-month posthearing aid fitting point. TRIAL REGISTRATION NUMBER: ISRCTN28090877.

Randomised controlled feasibility trial of the Active Communication Education programme plus hearing aid provision versus hearing aid provision alone (ACE to HEAR): a study protocol.

INTRODUCTION: Up to 30% of hearing aids fitted to new adult clients are reported to be of low benefit and used intermittently or not at all. Evidence suggests that additional interventions paired with service-delivery redesign may help improve hearing aid use and benefit. The range of interventions available is limited. In particular, the efficacy of interventions like the Active Communication Education (ACE) programme that focus on improving communication success with hearing-impaired people and significant others, has not previously been assessed. We propose that improved communication outcomes associated with the ACE intervention, lead to an increased perception of hearing aid value and more realistic expectations associated with hearing aid use and ownership, which are reported to be key barriers and facilitators for successful hearing aid use. This study will assess the feasibility of delivering ACE and undertaking a definitive randomised controlled trial to evaluate whether ACE would be a cost-effective and acceptable way of increasing quality of life through improving communication and hearing aid use in a public health service such as the National Health Service. METHODS AND ANALYSIS: This will be a randomised controlled, open feasibility trial with embedded economic and process evaluations delivered in audiology departments in two UK cities. We aim to recruit 84 patients (and up to 84 significant others) aged 18 years and over, who report moderate or less than moderate benefit from their new hearing aid. The feasibility of a large-scale study and the acceptability of the ACE intervention will be measured by recruitment rates, treatment retention, follow-up rates and qualitative interviews. ETHICS AND DISSEMINATION: Ethical approval granted by South East Coast-Surrey Research Ethics Committee (16/LO/2012). Dissemination of results will be via peer-reviewed research publications both online and in print, conference presentations, posters, patient forums and Trust bulletins. TRIAL REGISTRATION NUMBER: ISRCTN28090877.

Simultaneous suppression of tone burst-evoked otoacoustic emissions: Two and three-tone burst combinations.

Previous investigations have shown that components of a tone burst-evoked otoacoustic emission (TBOAE) evoked by a 1 kHz tone burst (TB1) can be suppressed by the simultaneous presence of a 2 kHz tone burst (TB2) or a pair of tone bursts at 2 and 3 kHz (TB2 and TB3 respectively). No previous study has measured this "simultaneous suppression of TBOAEs" for both TB2 alone and TB2 and TB3 from the same ears, so that the effect of the additional presence of TB3 on suppression caused by TB2 is not known. In simple terms, three outcomes are possible; suppression increases, suppression is reduced or suppression is not affected. Comparison of previously reported simultaneous suppression data suggests TB3 causes a reduction in suppression, though it is not clear if this is a genuine effect or simply reflects methodological and ear differences between studies. This issue has implications for previously proposed mechanisms of simultaneous suppression of TBOAEs and the interpretation of clinical data, and is clarified by the present study. Simultaneous suppression of TBOAEs was measured for TB1 and TB2 as well as TB1, TB2 and TB3 at 50, 60 and 70 dB p.e. SPL from nine normal human ears. Results showed no significant difference between mean suppression obtained for the two and three-tone burst combinations, indicating the reduction of suppression inferred from comparison of previous data is likely a result of methodological and ear differences rather than a genuine effect.

Further tests of the local nonlinear interaction-based mechanism for simultaneous suppression of tone burst-evoked otoacoustic emissions.

Tone burst-evoked otoacoustic emission (TBOAE) components measured in response to a 1 kHz tone burst (TB1) are suppressed by the simultaneous presence of an additional tone burst (TB2). This "simultaneous suppression of TBOAEs" has been explained in terms of a mechanism based on local nonlinear interactions between the basilar membrane (BM) travelling waves caused by TB1 and TB2. A test of this local nonlinear interaction (LNI)-based mechanism, as a function of the frequency separation (Δf, expressed in kHz) between TB1 and TB2, has previously been reported by Killan et al. (2012) using a simple mathematical model [Killan et al., Hear. Res. 285, 58-64 (2012)]. The two experiments described in this paper add additional data on the extent to which the LNI-based mechanism can account for simultaneous suppression, by testing two further hypotheses derived from the model predictions. Experiment I tested the hypothesis that TBOAE suppression is directly linked to TBOAE amplitude nonlinearity where ears that exhibit a higher degree of amplitude nonlinearity yield greater suppression than more linear ears, and this relationship varies systematically as a function of Δf. In order to test this hypothesis simultaneous suppression at a range of values of Δf at 60 dB peak-equivalent sound pressure level (p.e. SPL) and TBOAE amplitude nonlinearity from normal human ears was measured. In Experiment II the hypothesis that suppression will also increase progressively as a function of increasing tone burst level was tested by measuring suppression for a range of Δf and tone burst levels at 40, 50, 60 and 70 dB p.e. SPL. The majority of the findings from both experiments provide support for the LNI-based mechanism being primarily responsible for simultaneous suppression. However, some data were inconsistent with this view. Specifically, a breakdown in the relationship between suppression and TBOAE amplitude nonlinearity at Δf = 1 (i.e. when TB2 was reasonably well separated from, and had a higher frequency than TB1) and unexpected level-dependence, most notably at Δf = 1, but also where Δf = -0.5, was observed. Either the LNI model is too simple or an alternative explanation, involving response components generated at basal regions of the basilar membrane, is required to account for these findings.

Repeatability of sound-evoked triceps myogenic potentials.

OBJECTIVE: To investigate the repeatability of sound-evoked vestibular evoked myogenic potentials recorded from the triceps (tVEMPs) with and without visual feedback. DESIGN: tVEMP responses to 95 dB nHL 500-Hz tone bursts were recorded in a longitudinal, repeated measures study where P1 and N1 latencies and amplitudes were measured on three separate occasions from the same individuals. Analysis of variance, intra-class correlations, and limits of repeatability analyses were used to assess tVEMP repeatability and effects of visual feedback. STUDY SAMPLE: Fifteen participants (nine women) aged between 18 and 41 years took part. RESULTS: Response rates of 63% and 68% were obtained for tVEMPs with eyes open and closed, respectively. When present, tVEMP latencies and amplitudes exhibited fair to good repeatability. Repeatability of tVEMP latencies and amplitudes measured using Bland-Altman methods was poorer with eyes closed. CONCLUSIONS: Sound-evoked tVEMP response rates are too low to support their clinical utility at the moment. tVEMP response rate may be improved by refining the balance task to include a force related target. Better tVEMP repeatability with eyes open supports the hypothesis that the response is modulated by visual feedback, and is consistent with studies reporting triceps responses to galvanic stimulation.

A mechanism for simultaneous suppression of tone burst-evoked otoacoustic emissions.

Tone burst-evoked otoacoustic emission (TBOAE) components in response to a 1 kHz tone burst are suppressed by the simultaneous presence of tone bursts at higher frequencies. To date, the underlying cause of this "simultaneous suppression" of TBOAEs is unclear. This paper describes a potential mechanism based on local nonlinear interactions between basilar membrane (BM) travelling waves, and tests the extent to which it is able to account for this specific suppression phenomenon. A simple mathematical model based on local nonlinear interactions was developed, and its predictions for a range of tone burst pairs were compared to corresponding TBOAE suppression data recorded from fourteen normally hearing human ears at a level of 60 dB p.e. SPL. Model predictions and mean TBOAE suppression data showed close agreement for all pairs of tone bursts. These results suggest that simultaneous suppression of TBOAEs can be explained solely in terms of the local nonlinear interaction-based mechanism. However, the involvement of other mechanisms, involving components generated at places basal to their characteristic place along the BM, cannot be excluded.