Headphones and nonoccupational noise have long been the usual suspects in both lawmakers’ and mothers’ plans to reduce harm to people’s ears. Noise volume and duration of exposure can, over time, damage a person’s inner ear, making it difficult or impossible to hear frequencies at the extreme.

People above certain ages lose the ability to hear high frequencies primarily because nerves inside the ear — called hair cells — degrade as people age. When sound hits a person’s ear, the entering waves cause the ear drum to vibrate and send a string of vibrations through tiny bones in the ear, the cochlea, and into the hair cells, which eventually turn the sound vibrations into electrical impulses destined for the brain. As these hair cells are the first to encounter high frequencies, those frequencies are the first to go once the cells deteriorate.

Unlike other organs, the organ in the inner ear — called the Organ of Corti — doesn’t regenerate.

The hearing test for high frequencies was designed by AsapSCIENCE, a YouTube channel devoted to animated science videos. The test was entitled “How Old Are Your Ears?”

Much of the research into hearing loss suggests a growing danger in prolonged headphone usage. One study, published in JAMA, found hearing loss among adolescents aged 12-19 increased in prevalence from 14.9 percent in 1988-1994 to 19.5 percent in 2005-2006.

Worse, “adolescents and young adults typically underestimate symptoms of loud sound, tinnitus, and temporary hearing impairment during music exposure,” the researchers wrote, “and underreport concern for these conditions.”

Another study found that listening to music through headphones during exercise can be dangerous after more than half an hour at half volume, due to the increased blood flow to the limbs, which diverts blood away from the ears. The depleted supply of blood to the ears could leave the inner ear more vulnerable to damage from loud sounds, the researchers concluded.

And in 2009 the European Union issued a mandate for all music playing devices sold in the 27 member states requiring a device’s default volume be within safe levels.

“The mandate makes it clear that safe use depends on exposure time and volume levels. At 80 dB(A), exposure should be limited to 40 hours/week. At 89 dB(A) exposure should not exceed 5 hours/week,” a statement for the mandate read.

The National Institute on Deafness and Other Communication Disorders (NIDCD) says the threshold for hearing loss is 100 dB, and up to 130 dB — the noise level at the loudest rock concerts — the sound starts to become painful.