In the run-up to World Hearing Day (3rd March), the World Health Organization (WHO) and International Telecommunications Union (ITU) have released a new international standard for safe listening devices and systems.
Nearly 50% of people aged 12-35 years – or 1.1 billion young people – are at risk of hearing loss due to prolonged and excessive exposure to loud sounds, including music they listen to through personal audio devices.
Over 5% of the world’s population – or 466 million people – has disabling hearing loss (432 million adults and 34 million children); impacting on their quality of life. The majority live in low- and middle-income countries.
It is estimated that by 2050 over 900 million people – or 1 in every 10 people – will have disabling hearing loss.
Noise-induced hearing loss can be caused by a variety of environments and behaviours. For example, 40% of those frequenting such discotheques, clubs, sporting events or music concerts are exposed to potentially damaging sound levels. There is evidence that those exposed over the past 20 years to loud sounds in social settings are three times more likely to suffer hearing loss than those unexposed.
The widespread uptake of personal audio devices such as smartphones and MP3 players has added to this risk. Smartphone use in developing countries has grown from 45% in 2013 to 54% in 2015 and in in developed countries this figure stands at 87%.
It is estimated that 50% of those listening to music over their personal audio devices do so at levels that put their hearing at risk.
Hearing loss which is not addressed poses an annual global cost of US$ 750 billion.
Overall, it is suggested that half of all cases of hearing loss can be prevented through public health measures.
Noise-induced hearing loss in young children impairs language acquisition, learning disabilities, anxiety and attention seeking behaviours are also common in children exposed to loud sounds. Chronic noise exposure in classrooms affects academic performance in areas such as reading ability, comprehension, short and long term memory, and motivation. On average, children who are exposed to noisy learning environments have lower assessment scores on standardized tests, which in the long term might affect their academic and professional development.
In adults, unaddressed hearing loss can mean loss of earnings and difficulty in finding and retaining jobs. In Europe, for example, people with unaddressed hearing loss are twice as likely to be unemployed compared to their normal hearing peers. When employed they often earn lower wages, for example in the USA, wages are found to be between 50% and 70% lower for adults with unaddressed hearing loss. It affects social relationships and can be a cause for stress in domestic relationships.
Noise exposure in young people also contributes to age-related hearing loss that can lead to significant communication difficulties, with the subsequent emotional and cognitive effect this might imply. Recent evidence suggests that outcomes such as depression, isolation, frustration, cognitive decline, and decreased personal safety are twice as common among seniors with hearing loss than those without hearing loss.
While noise-induced hearing loss is irreversible, it can nonetheless be prevented. In the case of hearing loss caused by the unsafe use of personal audio devices, there are simple, effective practices such as keeping the volume within safe listening levels and limiting the time spent engaged in noisy activities that, if followed, can have a protective effect on people’s hearing.
The Safe listening devices and systems: a WHO-ITU standard recommends that personal audio devices include:
- “Sound allowance” function: software that tracks the level and duration of the user’s exposure to sound as a percentage used of a reference exposure.
- Personalized profile: an individualized listening profile, based on the user’s listening practices, which informs the user of how safely (or not) he or she has been listening and gives cues for action based on this information.
- Volume limiting options: options to limit the volume, including automatic volume reduction and parental volume control.
- General information: information and guidance to users on safe listening practices, both through personal audio devices and for other leisure activities.
The standard was developed under WHO’s “Make Listening Safe” initiative which seeks to improve listening practices especially among young people, both when they are exposed to music and other sounds at noisy entertainment venues and as they listen to music through their personal audio devices.
Volume limiting: This is a feature where by a volume-limiting message and option is automatically provided every time the user reaches 100% of their weekly allowance. The message should allow them the option to “continue listening” if they do not wish the device volume to reduce. When the message is not acknowledged, the default action will be to reduce the volume output to a pre-set level. If possible, users should be given the option to customize this level (the level at which they would like their device to limit the volume) according to their preference. The feature may also be used by individual users in order to limit their own sound exposure, if they wish to do so, by fixing the maximum output on their device.
Parental control: It is recommended that the device should offer an option whereby maximum sound output can be fixed and locked in the settings, possibly through use of a password. This would allow parents (or other adults) to limit the maximum sound output of the child’s device in a way that cannot be changed by the child.
WHO Standard levels for safe listening:
It is proposed that all personal audio devices should measure the listener’s exposure to
sound based on two possible operational modes of reference exposure:
Mode 1: WHO standard level for adults: this will apply 1.6 Pa2h per 7 days as the reference exposure (derived from 80 dBA for 40 hours a week).
Mode 2: WHO standard level for sensitive users (e.g. children): this will apply 0.51 Pa2h per 7 days as the reference exposure (derived from 75 dBA for 40 hours a week).
In order to estimate this, the device should be able to track the user’s volume level and time spent listening. Also, every device should have options for volume limitation and parental volume control.
Link to the WHO news release:
Link to WHO fact sheet on deafness and hearing loss (March 2018):