Nightclub, call centre employees could be at risk of noise-induced deafness: Experts

SINGAPORE: Complete hearing loss due to loud noises is commonly associated with workers dealing with heavy machinery, but employees at nightclubs, exercise studios and call centres may also be at risk of the condition, experts said. 

This comes as noise-induced deafness was listed as the top occupational disease in Singapore in a report by the Manpower Ministry released earlier this month. 

About 300 of such cases were reported in the first half of this year alone, accounting for close to two-thirds of all occupational diseases during the period. Those in the manufacturing industry,  especially metal-working, are at the highest risk of developing the condition. 

Clinical audiologist Alicia Tay told CNA that call centre employees, for instance, have sought help at The Listening Lab, where she heads its retail department.

“They have to always turn up the volume of their headphones in order to hear the person speaking over the phone, over the environmental noise. So they do come in with some symptoms of noise-induced hearing losses,” she said. 

She added that while it is less well-known, instructors who teach exercises like spin - a form of indoor cycling - several times a day may also be at risk of hearing problems.

“They play very loud music, and the instructors have to shout into a microphone in order for people to hear,” she noted.

“That combination of noise can sometimes exceed 100 decibels, and that is a risk of hearing loss because they're so often exposed for long durations.”

The maximum safe listening level is 85 decibels for eight constant hours. The duration of exposure that is considered safe “rapidly decreases” when it gets louder, Ms Tay pointed out. 

SYMPTOMS TO LOOK OUT FOR

There could also be a cumulative effect of noise, said Ms Tay. 

"People don't really consider the amount of sounds they're being exposed to outside of work, and that can definitely count into the amount of hours of being exposed to. (That’s) something that they need to be aware of as well outside of work."

The average person is exposed to loud sounds from headphones, concerts, and riding motorcycles on the road, she said.

Noisy traffic is considered to be around 80 decibels, while an aircraft taking off - which can be a day-to-day noise for some - registers at about 130 decibels, said Dr Joseph Lim, head of Tan Tock Seng Hospital’s occupational and environmental health and safety department.  

He added that although the risk for employees is not insignificant, it is much lower than for those who work in traditional heavy industries.

People who have advanced cases of noise-induced deafness can have symptoms such as being unable to hear or discern speech accurately, said Dr Lim.

They may also experience symptoms of tinnitus - or ringing in the ears - as well as poor sleep, irritability and poor mood. 

“These can result in factors such as being unable to hear spoken instructions clearly, having difficulty communicating with colleagues, and also not being able to hear alarms or shouted warnings,” he said.

Ms Tay said that those suffering from the condition put in a lot of effort to hear, so they are often tired throughout the day. Because of this, they tend to withdraw from social situations, which can lead to depression, she added. 

WHAT EMPLOYEES AND EMPLOYERS CAN DO

Noise consultant Daniel Tan said that basic awareness of the risk of noise-induced deafness is important, which could be boosted through the use of posters.

Limiting exposure to noise by taking a break every 45 minutes also helps, he noted. 

He suggested that workplaces could install a noise meter and go one step further to set a threshold.

“If the noise exceeds a certain safety … level, it can alert the user. And if it happens that it exceeds, they can implement preventive measures to mitigate (or) take some action to resolve it,” he said.

Ms Tay said that spin instructors, for instance, can turn down the volume so they do not have to shout over music. Wearing hearing protection earplugs is very useful, she added.

These can be bought over the counter, but buying a well-fitted pair from audiologists protects the ears better, she said.

People who need to listen to loud music for work, like employees at concert venues and nightclubs, can buy music-filtered earplugs, which protect the ears from loud sounds without sacrificing the fidelity of music, she added. 

Sound level meter apps that can be downloaded on phones are also a good way to gain awareness of how much noise they are being exposed to, she said.

In general, people can also consider using noise-cancelling headphones so they can avoid increasing the volume of their devices to compensate for their environments, Ms Tay said. 

Another suggestion she gave was to follow the 60-60 rule.

“It suggests that you should not listen to sounds above 60 per cent of the maximum volume of your phone for more than 60 minutes at a time, and you should take regular breaks as well,” she added.