Healthy heaAring for Healthy Ageing: Data-driven Hearing Rehabilitation Intervention to Promote Healthy Hearing

A Speech-in-Noise test, validated for the Finnish language. In the test participants will listen to five-word sentences chosen out of a standardized and optimized word matrix under stationary background noise (65dB SPL). The result of the FMST is the signal-to-noise ratio (SNR) at which the participant identifies 50% of the presented word items correctly, this is called the speech reception threshold (SRT50).

A Speech-in-Noise test, validated for the Finnish language. The word material of the test consists of digit triplets presented under stationary background noise (65dB SPL). The result of the DIN is the signal-to-noise ratio at which the participant identifies 50% of the presented triplets correctly, this is called the speech reception threshold (SRT50).

The SSQ questionnaire is a self-reporting hearing questionnaire that comprises 49 questions divided into three subdomains: Speech Perception (SP), Spatial Hearing (SH) and other qualities of Hearing (SQ) (18). The answers are provided on an 11-point Likert scale, ranging from 0 to 10.

Usage rates of HAs (hours per day) are regularly checked via the HAs' log-data source and recorded during every clinical visit. In addition, participants' own estimation of usage rates is inquired and recorded.

Listening effort will be self-reported by the participant for listening tasks of varying difficulties (i.e., different signal-to-noise ratios) on a 10-point VAS scale.

Response time for the answers given by the participant will be calculated and recorded automatically

The THI is a 25-item self-report questionnaire for tinnitus that has Functional, Emotional and Catastrophic subscales. It has excellent convergent validity, construct validity and test-retest reliability. The THI takes 10min to complete. Scoring takes 5 min with a score of 4 for a 'yes', 2 for 'sometimes' and 0 for 'no'.

The Finnish version of the CERAD (Consortium to Establish a Registry for Alzheimer´s Disease) test battery is recommended for assessment of memory disorders in the national Current Care Guidelines developed by the Finnish Medical Society Duodecim (www.kaypahoito.fi).

CDR (Clinical Dementia Rating) is used to assess the influence of cognitive impairment on the ability to conduct everyday activities in people with AD and gives a global clinical impression of the functioning level of the study participant. The assessor will interview the participant regarding their cognitive performance on six domains: memory, orientation, judgment and problem solving, community affairs, home and hobbies, and personal care. Each domain is rated on level of impairment: 0 (none), 0.5 (questionable), 1 (mild dementia), 2 (moderate dementia) or 3 (severe dementia). The total Sum of Boxes ranges from 0 (no impairment) to 18 (severe impairment on all domains).

A generic, comprehensive, standardized, self-administered questionnaire of health-related quality of life developed in Finland. It includes 15 questions providing a numerical score for patient-perceived health status. It can be used both as a profile and single index score measure. It is commonly used in Finland to assess quality of life in standard care.

A concise, generic measure of self-reported health which is accompanied by weights reflecting the relative importance to people of different types of health problems

A short, self-administered questionnaire to quantify psychological and physical symptoms of depression. It includes 21 items, and participants are asked to rate each item using a 4-point Likert scale. The BDI is one of the most frequently used questionnaires for the assessment of depression in clinical practice, including in older adults.

The HERE questionnaire is self-reporting hearing questionnaire validated in Finnish language (28). It includes 15 items with a numeric rating scale from 0 to 10 for each item and allows the assessment of hearing with and without hearing aids.

The possible cortical changes related to the use of HA will be measured through EEG-derived cortical auditory evoked potentials (CAEPs) assessed while administering the DIN test.

sMRI will provide measures of neurodegeneration (e.g., cortical thickness, brain volumes) and cerebrovascular pathology (e.g., white matter lesions, clinically "silent" infarcts). The scans will include T1, T2, FLAIR, and diffusion weighted sequences (~45 min).

Task-based fMRI scans (~20 min) will be conducted on at least of 30 participants from both groups (60 altogether) closely mimicking the EEG-paradigm (section 3.3.1). To minimize the possible masking effect of scanner noise, the sounds will be presented during silent periods between scans.

Task-based ultra-short- and zero echo time MRIs (UTE, ZTE) (~20 min) will also be conducted on the same group of participants having the fMRI described previously. The tasks will closely mimic the EEG-paradigm (section 3.3.1). Short echo time sequences are less sensitive to susceptibility and motion artifacts and the sequences are silent.

Participants will receive a self-administered questionnaire covering several lifestyle domains potentially affected by HI and relevant for dementia risk, e.g. physical, cognitive and social activities. An active lifestyle index will be calculated as a composite score based on these domains.

The cognitive test battery includes tests covering different cognitive domains, and available within the public domain. It was adapted and already tested for persons with HI by Prof. Vincent Lin at Sunny Brook University Hospital, Canada, by converting all original verbal instructions into a visual PowerPoint presentation shown on a computer screen. In the HAHA trial, the cognitive test battery will be self-administered by the participant on the DigiKuulo screen at the study site.

Best-corrected visual acuity

Slit-lamp examination

Retinal imaging

Eye geometrics and biometric values

Frozen and stored for future assessment of HI or dementia- related markers (e.g. genetic, amyloid, tau, neurodegeneration)

Amplification of HAs

Amplification of HAs