Headphone and earbud volume limits: what the WHO's safe listening figures mean for buyers

Most people do not know how loud their headphones are in decibels, the World Health Organization (WHO) points out, yet the level of the sound and how long you listen to it decide the risk to your hearing. WHO's safe listening figures add the two together over a week, and the WHO-ITU standard for personal audio devices asks phones and players to keep that count for you. Here is what the figures say, and what they mean for volume caps, noise canceling and the settings worth switching on.

The stakes are large. WHO says unsafe listening practices put more than 1 billion young adults at risk of permanent hearing loss that could be avoided. The U.S. National Institute on Deafness and Other Communication Disorders (NIDCD) says hearing loss can result from long or repeated exposure to sounds of 85 A-weighted decibels (dBA) or more, and it lists music through headphones at maximum volume, along with sporting events and concerts, at 94 to 110 dBA.

How long is safe: WHO's weekly figures

WHO counts 80 dB as safe for up to 40 hours a week. Each 5 dB step above that cuts the weekly allowance sharply, and at 120 dB it is measured in seconds.

Set NIDCD's range for headphones at full volume, 94 to 110 dBA, against the table: across WHO's rows from 95 to 110 dB, the weekly allowance shrinks from 1 hour 15 minutes to 2.5 minutes. Read the other way, each 5 dB taken off the level multiplies the safe weekly time by between 2.5 and almost 4 in WHO's table.

What the WHO-ITU standard asks devices to do

In February 2019, WHO and the International Telecommunication Union (ITU) issued a voluntary standard for safe listening devices and systems, aimed at the personal audio devices people use to listen to music and other audio. Its recommendations come in four parts.

WHO's advice to listeners points the same way: prefer phones and headphones that come with safe listening features already built in, such as sound exposure monitoring and volume limiting. If you use an app to check your levels, WHO says to stay below an 80 dB average.

Volume caps on children's headphones

If headphones are sold with a maximum volume, WHO's numbers show what that figure allows. A cap limits how loud the sound can get, not how long a child listens. At 85 dB, WHO's general table allows 12 hours 30 minutes a week, and the WHO-ITU standard sets a lower reference for children than for adults: 75 dB for 40 hours a week, against 80 dB. A cap and a weekly count do different jobs, and the standard asks for both kinds of protection: the allowance tracking and a parental volume control that a parent can lock.

Fit and noise canceling

WHO recommends well-fitted, noise-canceling headphones, because they reduce the need to raise the volume in noisy settings such as public transport or a cafeteria. For commuters, that makes a good seal and active noise cancellation worth weighing as hearing features, not only comfort ones.

• Keep the volume below 60% of the maximum, as WHO advises.
• Take breaks from loud sound, preferably somewhere quiet, so your ears can rest.
• Check the room: WHO says that if someone at arm's length can only hear you when you raise your voice, the sound around you is too loud.
• Use the exposure tracking on your phone or an app. WHO names the NIOSH-SLM app for measuring sound levels around you.

How WHO's figure compares with the workplace limit

For workers, the National Institute for Occupational Safety and Health (NIOSH) treats noise of 85 dBA or more as hazardous, and its recommended exposure limit is 85 dBA averaged over an eight-hour workday. By its count, about 27 million workers face hazardous noise on the job every year. WHO's reference for listening is set at a lower level, 80 dB, spread over 40 hours a week.

Signs to watch for

Noise-induced hearing loss often comes on gradually and can go unnoticed, WHO says, and NIDCD notes that it can be temporary or permanent, but that it can be prevented. WHO lists these signs of possible hearing loss:

• Ringing in the ears that persists (tinnitus).
• Difficulty hearing high-pitched sounds, such as birdsong, doorbells, telephones and alarm clocks.
• Trouble understanding speech, especially on the telephone.
• Difficulty following conversations in noisy places, such as restaurants.

If you notice any of them, WHO advises getting your hearing checked. Our guide to Bluetooth LE Audio and Auracast covers another feature to check on a spec sheet.