More than 1·5 billion people experience some degree of hearing loss, a number that could increase to 2·5 billion by 2050, according to WHO's World Report on Hearing. Hearing loss is often seen as an invisible disability. Not only because it is not associated with visible signs but also because it does not receive the attention it should.

The consequences of hearing loss can be profound. Untreated hearing loss can be associated with unemployment, social isolation, and affect quality of life. In children, hearing loss can affect spoken language and development. In adults, untreated hearing loss is associated with cognitive decline and dementia. WHO estimates that unaddressed hearing loss poses an annual global cost of US $980 billion (including costs of educational support, loss of productivity, and societal costs). Importantly, hearing loss can be prevented but remains commonly undetected and is too often seen as a consequence of ageing. Limited awareness and stigma have contributed to this situation. Recognising hearing loss as an increasing public health issue that affects people of all ages is crucial.

In 2021, WHO outlined the H.E.A.R.I.N.G. package, recommending key public health interventions to address hearing loss across the life course, focusing on prevention and early intervention. Disabling hearing loss affects 34 million children. Yet, almost 60% of childhood hearing loss can be prevented through measures such as immunisation or improved prenatal and neonatal care. Among young people, 50% are at risk of avoidable hearing loss due to unsafe sound levels from personal audio devices and 40% at entertainment venues. During adulthood, minimising loud noise exposure in the occupational, recreational, and environmental settings can reduce hearing loss occurrence and delay the onset of age-related hearing loss. In addition, measures including screening for early detection of hearing loss are important. However, progress has been slow. Universal hearing screening for newborns, school screening for children, and regular screening for adults aged older than 50 years have been recommended by WHO, but implementation of such guidance varies around the globe.

Among older adults, timely intervention could help prevent cognitive decline and dementia, which is associated with hearing impairment. In this issue of The Lancet Public Health, Fan Jiang and colleagues report that people with hearing loss not using hearing aids could be at higher risk of dementia than those without hearing loss. Those using hearing aids did not appear to be at an increased risk of dementia. Although further research is needed to ascertain a causal relationship, for Gill Livingston and Sergi Costafreda writing in a linked Comment, the evidence on hearing aids is as good as it gets without randomised controlled trials, which might not be practically possible or ethical. However, hearing aids are underused. Hearing aids are provided for free by the UK National Health Service, France recently increased the reimbursement of hearing aids, and the USA has enabled the purchase of over-the-counter hearing aids for people with mild to moderate hearing loss.Nevertheless, to increase the use of hearing aids, beyond removing affordability and accessibility barriers, it is necessary to increase awareness and address the stigma associated with stereotypes and misconceptions.

There is a clear need to address hearing loss as a social challenge. Greater community engagement, educating people about hearing loss and how to protect their hearing health could help address the roots of stigma and ensure people seek help when needed. Health professionals have a central part to play to raise awareness around hearing health, as recently shown in Belgium with a campaign directed at General Practitioners providing information on hearing loss and its associated consequences on health and wellbeing, to recognise hearing loss, discuss it, and refer patients.

Hearing loss is a modifiable determinant of health and wellbeing. Policy makers should realise the huge benefits (including economic benefits) of taking action. Investing in hearing health through the integration of WHO‘s recommended H.E.A.R.I.N.G. interventions could result in a return of US $16 for every dollar invested. Prevention across the life course will be key. Governments, health professionals, and civil society can help reduce the burden of hearing loss, tackle stigma, and support people of all ages.