Comparing remote and in-clinic hearing aid fittings

Participants will have 2 hearing aid fitting interventions (repeated measures, double-blind crossover design): one following standard 'in-clinic' protocols including Real Ear Measurements (on-ear output verification) and one following remote/teleaudiology protocols. For each intervention, participants will wear the hearing aids for 4 weeks with opportunity for subjective sound adjustments. There will be a 2 week 'wash out' period between interventions. At the end of each intervention, final hearing aid output will be measured using Real Ear Measurements. Total study duration is 12 weeks, including periods between interventions. Protocol adherence will be monitored at the follow-up appointments through hearing aid data-logging. In-clinic fitting protocol (duration 60 mins): For the initial in-clinic hearing aid fitting, participants will be fit binaurally with premium-level, rechargeable, receiver-in-the-canal hearing aids. The receiver and dome configuration will be chosen using standard clinical procedures and be consistent for each participant for the duration of the study. The hearing aids will be programmed through the manufacturer’s software to 100% acclimatisation using the National Acoustics Laboratory Non-Linear 2 (NAL-NL2) prescription targets for long-term hearing aid wearers. REAR will be verified using a Natus Aurical Freefit and Otometrics Otosuite PMM module, with the gain settings adjusted through hearing aid software to meet NAL-NL2 targets for soft (55dB), medium (65dB) and loud (75dB) stimuli using the International Speech Test Signal. On-ear measurement of maximum power output will be measured at 85dB to ensure estimated uncomfortable loudness levels are not exceeded. Where hearing aid programming features are available for an in-clinic session but are not available for a remote session, these will be removed from the in-clinic fitting protocol to maintain blinding for the clinicians performing the follow-up appointments. Hearing aid settings will be optimised using subjective participant feedback to balance overall volume, perceived sound quality, and perception of own voice/occlusion. This process will follow an interview-style approach, with the participant asked to comment on each component and the audiologist making small adjustments to the hearing aid settings until the participant is satisfied with the sound. The hearing aid setting will then be stored and the hearing aids retained at the clinic. Remote/teleaudiology fitting protocol (duration 60 mins) Approximately two weeks after the in-clinic hearing aid fitting, a remote hearing aid fitting appointment will take place. The time interval is to allow participants’ memory of the sound of the in-clinic programming to decay so that it is less likely to influence the remote fitting. The same hearing aids used at the in-clinic hearing aid fitting will be reset in-clinic and programmed through hearing aid software to 100% acclimatisation using NAL-NL2 prescription targets for long-term hearing aid wearers. The hearing aids will be programmed to allow for a remote hearing aid connection. The hearing aids will be sent to the participant via courier. At the scheduled hearing aid fitting appointment time, the audiologist will telephone the participant to confirm the app installation and Bluetooth pairing was successful. The participant and audiologist will then connect through the app for a remote support session. Remote support allows an audio-video link between the participant and audiologist. The audiologist will connect to the participant’s hearing aids through a Bluetooth connection with the participant’s smartphone or tablet. When both the participant and the audiologists are connected to the remote support appointment, the audiologist will perform proxy verification measurements through the hearing aid manufacturer software. Hearing aid settings will be optimised using subjective participant feedback to balance overall volume, perceived sound quality, and perception of own voice/occlusion. This process will follow an interview-style approach, with the participant asked to comment on each component and the audiologist making small adjustments to the hearing aid settings until the participant is happy with the sound. The hearing aid settings will be saved, and the participant will return the hearing aids to the clinic through return-post courier. First and Second Intervention Protocol (duration 30mins each) The hearing aids will be programmed with the pre-saved settings that relate to each participant’s group allocation. Two weeks after the final fitting appointment, the participants will be sent the hearing aids via courier. They will be instructed to wear them for at least 8 hours per day for two weeks. At the end of these two weeks, all participants will have a follow-up appointment via remote support with an audiologist who is blinded to the groups. At this appointment, the participants will have the opportunity to have the hearing aids settings adjusted by the audiologist in order to optimise the sound for their personal preferences. This process will follow an interview-style approach, with the participant asked to comment on overall volume, overall sound quality, performance in quiet, performance in noise, and perception of own voice. The audiologist will make small adjustments to the hearing aid settings until the participant is satisfied with the sound. Participants will be instructed to wear the hearing aids for a further two weeks, and then return to the clinic for the first outcome assessment. The hearing aids will be returned to the clinic at this time. The second intervention will follow the same process as the first, with the hearing aids programmed with the alternate settings.