hang Xiaomeng never imagined it would happen to her. Last year, doctors diagnosed her with significant hearing loss. She was 25, but had been listening to music through
earphones at least three hours a day for nearly eight years.
In March 2018, Zhang began hearing a constant ringing in her left ear. It eventually became so loud that she couldn’t hear her coworkers speak. She went to a major hospital in South China’s Guangdong Province, where doctors found she could not hear sounds less than 40 decibels. (Normal hearing ranges from 0 to 20 decibels for all frequencies.)
“Maybe your hearing was damaged from long-time use of earphones, lack of sleep or abnormal blood circulation in the ear,” Zhang recalled her doctor saying. After three months of treatment, Zhang partially recovered her hearing, but still suffers from tinnitus.
Zhang’s case is not unique. Several audiologists told our reporter that prolonged exposure to high volumes can cause irreversible damage. Statistics from the World Heath Organization (WHO) show that 1.1 billion people aged between 12 and 35 are at risk of hearing loss from excessive exposure to loud sounds, including listening to music through audio devices. Experts estimate that by 2050, more than 900 million people will suffer from disabling hearing loss.
Liu Bo, deputy director of the Beijing Institute of Otolaryngology, told NewsChina that he sees one or two young people a day complaining of issues from using earphones at high volumes.
“Over the years, a growing number of younger people are seeking treatment for hearing impairment caused by earphones,” he said. “A majority of them are college students who damaged their hearing from recreational noise.” Liu added that 12 to 15 percent of college students are affected by sustained recreational noise that will result in hearing damage between five and 10 years.
In 2017, the Medical School of Qinghai University surveyed 1,616 college students in Qianghai Province and found that 36.38 percent suffered from noise-induced hearing damage. Fourth-year students were 1.4 percent more likely to have hearing issues.
According to a study published in the Journal of Clinical Otorhinolaryngology Head and Neck Surgery in 2015, 23.98 percent of college students have the habit of sleeping with earphones on. Among them, more than half said they turn up the volume to compensate while in noisy environments.
In another survey from 2017 conducted by Xinhua College of Sun Yat-sen University in Guangdong Province, 77 percent of college students said they usually use earphones, 80 percent use them up to three hours a day and 12 percent would listen at volumes as high as they could.
According to the Diagnosis Standards on Occupational Hearing Impairment released by China’s Ministry of Health in 2007, exposure to noise above 85 decibels for eight hours at a stretch is likely to result in occupational hearing damage.
“Nowadays, noise is increasingly affecting human hearing, particularly for those who frequently use audio devices,” Qin Caihong, a doctor at the Civil Aviation Medical Center, told NewsChina.
Qin, who conducts hearing tests for potential pilots, has found that college students are more likely to have hearing conditions than those in high school and middle school.
Liu Hui, chief physician at the Department of Otolaryngology of Tongren Hospital in Beijing, told our reporter that medically there are degrees of deafness. “Patients with minor hearing damage are unable to hear whispers,” he said. Doctors define moderate deafness as only able to hear sounds between 41 and 60 decibels. This means spoken conversation at normal levels is inaudible. Patients who can only hear sounds above 81 decibels must use hearing aids.
Liu Yingjie, a senior engineer with the China Railway Design Corporation, conducted a study on the effects of noise at 10 subway stations in six cities nationwide in 2009. Liu discovered that an arriving train produces noise at 90 decibels. In such an environment, passengers will unconsciously increase the volume of their earphones. “It’s the equivalent of putting an electric drill (100 decibels) or a propeller-driven aircraft in your ear,” he said.
According to the WHO, exposure to 85 decibels for eight hours or 100 decibels for 15 minutes can lead to temporary hearing loss or a ringing in the ears. Long-term exposure can cause permanent hearing damage.
On February 12, 2019, the WHO and the International Telecommunication Union (ITU) issued a new international standard for the manufacture and use of personal audio devices, including smartphones, to protect young people from excessive volumes.
“Given we have the technological know-how to prevent hearing loss, it should not be the case that so many young people continue to damage their hearing while listening to music,” said Tedros Adhanom Ghebreyesus, director-general of the WHO, in an article posted on the organization’s website. “They must understand that once they lose their hearing, it won’t come back. This new WHO-ITU standard will do much to better safeguard these young consumers as they go about doing something they enjoy.”
The safe listening standards require personal audio devices to inform users when volumes are not safe. Also, functions such as automatic volume reduction and parental volume control should be designed to kick in, particularly in noisy environments.
According to a 2017 consumer report on headphones and earphones in China released by GfK, a market and consumer information consultancy, people between 19 and 33 are the main consumers of mid- and high-end earphones, most of whom are college students and office workers. The consultancy added that in 2017, sales of earphones in China increased by 35 percent year-on-year.
In 2015, students from electrical and civil engineering schools of Chongqing University conducted a study on the effects of different earphones. They found that in-ear devices, such as earbuds, are most likely to cause hearing damage and that noise-cancelling headphones are somewhat effective in reducing noise levels in loud places such as subway stations, airports and construction sites.
“Noise cancelation hearing devices could reduce harm to the hearing system caused by noise. Hearing impairment depends on three factors – duration, intensity and frequency,” Liu Hui, chief physician at the Department of Otolaryngology of Beijing-based Tongren Hospital, told NewsChina.
Liu Bo, deputy director of the Beijing Institute of Otolaryngology, expressed the urgent need for public awareness campaigns in China. “We generally accept the 60/60 rule: Keep the volume of earphones at no more than 60 percent and listen for a maximum of 60 minutes at a stretch,” he said. “If other people around you can hear your earphones, it’s too loud.”