The Mental Cost and Burden of Listening

Participants will be asked to allocate up to 1.5 hours of their time for each of the 3 visits to the lab.

(in fact all activities planned for each visit are estimated to take less than an hour but we are accounting for time to discuss things and allow for questions if needed)

I- Hearing tested:

Once screened over the phone and invited into the lab, all participants will have their hearing tested through PTA thresholds in the lab, done by trained clinical audiologists. This will include standard audiological assessments including otoscopy, obtaining real ear measurements and removing ear wax only if any wax is blocking the ear canal if the participant consents, in order to facilitate the function of the hearing aid so that we avoid wasting the participant's time and study resources.

II- Test Battery:

Both test and control groups will complete a test battery twice: 2 weeks before the hearing aid fitting or the equivalent education session for the control group, and 4 weeks after it. They will also be asked to use a sleep and step tracking device for 2 weeks before, and 4 weeks after the hearing aid fitting / education session. The total number of visits that the participants will be required to make to the lab is 3, during 2 of which they will complete the test battery. The battery is hosted on Gorilla, an experiment platform and presented to them on a university laptop in one of the assigned rooms in the lab.

The test group and the control group will complete the same test battery the same number of times (twice as pre and post-tests).

The test battery is made up of:

1. Demographic questions about age, gender, and whether English is their primary language.
2. The following questionnaires: Pittsburgh Sleep Quality Index - Reduced Morningness-Eveningness Questionnaire - Revised Hearing Handicap Inventory and Screening Tool along with one additional question about whether they have used hearing aids before - WHO-5 questionnaire - Fatigue and Caffeine Screening Questions.
3. Then they will complete the following two groups of tasks which will be counterbalanced:

• Listening Tasks: Discourse Comprehension Task to Running Speech in Noise (competing speaker) divided into four parts with an Effort visual analogue scale (from NASA-TLX) asking about their effort at each stage - A visual analogue likert scale for Fatigue is requested once before and once after the listening tasks - A speech perception in noise test (multi-speaker babble) where the participants are asked to type whatever they could hear from a sentence spoken in noise (a standardised test that uses AzBio sentences) - A Mental Demand visual analogue scale (from NASA-TLX) is done once at the end of the listening tasks. The listening tasks take around 20 minutes to complete.
• Cognitive task: Attention Network Test, which takes place for around 20 minutes. It requires the participant to click a keyboard button in relation to the direction of an arrow shown in the centre of the screen over many trials. The arrow is flanked by other arrows that either point in the same direction as the central arrow, or opposite direction, or are straight lines instead of arrows.

All of these assessments in the test battery are either multiple choice questionnaires, or tests where participants press a key on their keyboard in response to visual stimuli on their screen according to a set of instructions. It takes one hour to complete.

III- Intervention:

The test group will be asked to use hearing aids that are fitted specifically for them by clinical audiologists on the research team according to the best practice standards. The hearing aids are state of the art and brand new, provided by SONOVA. The clinical audiologists took part in a training for the specific fitting of SONOVA hearing aids. The control group will not receive this intervention but would take part in an educational session about hearing care solutions instead. The fitting will be customised and every participant will have had ample time to test them before they leave the lab.

SONOVA AG confirms that the hearing aids that this study will trial meet the requirements of the Medical Device Regulation (EU) 2017/745 as well as the Radio Equipment Directive 2014/53/EU, each participant assigned to using the hearing aids can communicate with the research team at any time in case of questions or requests, and will take home all the necessary equipment such as a UK charger and the accessories, and will be trained on how to use them and take care of them. They will also take home a booklet of information for users of the device provided by the manufacturer. The researcher will follow-up with them to make sure that the use of the device is comfortable, see part V below.

IV- Tracking:

Both groups will be asked to use a sleep and step count tracker (in the same device) provided by Activinsights, a device made specifically for clinical trials and research. This device is worn on the wrist like a watch without a screen and it is waterproof, they will be asked to keep it on their wrist day and night for the duration of 6 weeks, 2 of which are before the intervention/education seesion and 4 after. The battery of this device lasts for longer than that so the device will not need any maintenance during that period, it will be given to them fully charged. The data that will be collected from this tracker are step count per day, and sleep efficiency per night, that are calculated based on the device's algorithm for sleep and step tracking.

The actigraph provided by Activinsights called GENEActiv is FDA 510(k) exempt and is a European Class I Medical Device. The participants will take home a leaflet provided by the manufacturer with details about the device, and participants can communicate with the research team at any time if they are experiencing any inconvenience from it. The PI will ensure that the device is working, fully charged, and ready to go before the participant leaves the lab (no charging or maintenance will be required for it).

V- Phone call follow-up:

All participants will be called twice to check in on them regarding their comfort with the device usage, for the test group that entails their use of the hearing aids and the tracker, and for the control group that entails only the tracker. This will include questions about whether they are inconvenienced by the devices, having any negative reactions to anything, and for those using hearing aids additional questions will be based on the Device Oriented Subjective Outcomes DOSO (b) questionnaire which will also be asked at the end of the trial upon returning the hearing aids. This will make sure that the participant receive the support that they need during the period when they are using the devices for the experiment, a script of the call interview questions is attached. The control group participants will be called 3 weeks after the use of the tracker and 5 weeks after, and the test group participants will be called 1 week after hearing aid fitting and 3 weeks after that, and during the hearing aid fitting / education session we will check on all participants' comfort with the sleep tracker in person (forming a third check-up).

VI- Optional EDI Monitoring:

Participants are invited to complete an extra optional online questionnaire to monitor characteristics for the purpose of equality, diversion and inclusion (EDI). As part of the Manchester Biomedical Research Centre (who have advised on the questions asked), we have a commitment to improve access to research participation for diverse communities. In order to do that we need to collect information around characteristics of research participants to identify gaps and develop strategies to deal with these.