Against the backdrop of global population aging, age-related hearing loss (ARHL) has reached epidemic proportions and is increasingly recognized as an independent risk factor for cognitive decline and other major neurodegenerative diseases. This study aims to systematically develop an integrated framework for the early warning, precise assessment, and intervention management of ARHL.

Using a national multicenter design, the project will establish a prospective cohort of more than 3,000 older adults. We will integrate multimodal data including audiological tests, cognitive function assessments, and blood biomarkers, and employ artificial intelligence and unsupervised machine learning methods to address critical bottlenecks in the field: the unclear mechanistic link between ARHL and cognitive decline, and the lack of validated predictive tools.

Specifically, this study will: (1) develop data-driven clinical classification criteria for ARHL; (2) create a personalized "Hearing Health Clock" predictive model; (3) identify minimally invasive blood biomarkers for early detection of cognitive impairment; and (4) formulate a multidimensional early dementia screening program suitable for community-wide implementation. The findings will provide scientific evidence and practical tools for the prevention and control of hearing and cognitive health risks in older adults in China.

Inclusion Criteria:

1. Aged 60 years or older.
2. Clear consciousness and able to cooperate with all study assessments and examinations.
3. Permanent local residents who have lived in the area for at least 9 months per year and are willing to complete long-term follow-up.

long-term follow-up：

1. Diagnosis of sensorineural hearing loss.
2. Bilaterally symmetric hearing with air conduction threshold difference ≤15 dB at 0.5 kHz, 1 kHz, 2 kHz and 4 kHz between two ears.
3. Hearing loss not caused by non-age-related factors.

Exclusion Criteria:

1. Unable to complete pure-tone audiometry and other auditory examinations. History of central nervous system diseases, including Parkinson's disease, stroke, intracranial tumor or brain trauma.
2. Severe uncontrolled systemic diseases (cardiac, pulmonary, hepatic, renal insufficiency) or advanced malignant tumor with expected survival less than 3 years.
3. Any other condition judged by the investigator inappropriate for study enrollment.

This study enrolls community-dwelling adults aged 60 years and older from multiple medical centers in China. All participants are permanent local residents with annual residence of no less than 9 months, clear consciousness, and able to cooperate with standardized audiological examinations, cognitive function assessments, questionnaire surveys and blood sample collection.

A total of more than 3,000 older adults will be recruited for the cross-sectional baseline survey. Among them, a sub-cohort of no fewer than 150 older adults with sensorineural hearing loss, bilaterally symmetric auditory thresholds without middle ear disorders, and no non-age-related causes of hearing impairment will be included for 3-year annual longitudinal follow-up.

Individuals with inability to complete pure-tone audiometry, established neurological diseases, severe organ dysfunction, advanced malignant tumor with short life expectancy, or any other inappropriate conditions assessed by investigators are exclud