The World Health Organisation (WHO) has launched "hearWHO", a free application for mobile devices, which allows people to check their hearing regularly and intervene early in case of hearing loss to mark the World Hearing Day.

WHO annually marks World Hearing Day every March 3.

A statement issued by Tarik Jašarevic of the WHO said the app is targeted at those who were at risk of hearing loss or who already experienced some of the symptoms related to hearing loss.

The statement said among those who would particularly benefit from this new tool include people who were often exposed to high levels of sound, such as those who listen to loud music or work in noisy places; people who use medicines that were harmful to hearing; and people aged above 60 years.

It said symptoms indicating the onset of hearing loss included a ringing sensation in the ear, known as tinnitus; frequently missing parts of a conversation; or a tendency to increase the volume of television, radio or audio devices.

The statement said early detection of hearing loss was crucial to identify risky behaviours that needed to be changed and ascertain the most appropriate intervention needed to address hearing loss.

It said such interventions were identified by hearing care professionals and could range from captioning and sign language to hearing aids and cochlear implants.

It noted that interventions to prevent, identify and address hearing loss were cost-effective.

"Many people with hearing loss are unaware of it and as such they miss out on educational, professional and everyday-life opportunities," said Dr Etienne Krug, Director of the WHO Department for the Management of Non-Communicable Diseases, Disability, and Violence and Injury Prevention.

"Regular hearing checks ensure that hearing loss is identified and addressed as early as possible," he added.

The statement said the hearWHO app was based on a validated digits-in-noise technology: users are asked to concentrate, listen and enter into their mobile devices a series of three numbers when prompted.

It said these numbers had been recorded against varying levels of background sound, simulating listening conditions in everyday life.

It said the app displayed the users' score and its meaning and stores the outcome of the test so that the user could monitor hearing status over time.

It said reminders to take the test regularly, could be set by users.

It noted that the app could be used by individuals as well as health care providers with a view to facilitating hearing screening, especially in low-resource settings.

"Above all, this app will help us increase awareness of the importance of ear and hearing care," said Dr Shelly Chadha, WHO Technical Officer.

"Once lost, hearing does not come back. Through World Hearing Day, and with the support of this app, we encourage people to 'Check your hearing!' in order to help preserve this valuable gift that helps us to enjoy life," she stated.

The statement said over five per cent of the world's population - or 466 million people - had disabling hearing loss (432 million adults and 34 million children).

It is estimated that by 2050 over 900 million people - or one in every ten people - would have disabling hearing loss.

Globally, hearing loss which had gone unaddressed posed an annual cost of $ 750 billion.