Noise

The risk of noise & common sources of noise

Noise can be defined as sound undesired by the recipient. Besides being a nuisance, noise can interfere with working efficiency and hinder communication between colleagues. It can also cause accidents by masking warning signals, but most importantly, it can damage our hearing.
Noises are everywhere at a workplace, but harmful noises are often from the following:

  • Electric motors
  • Woodworking machines
  • Compressors
  • Ventilator and Exhaust Fans
  • Pneumatic tools
  • Airplanes noises
If your workplace consists of the above noises, be aware of them and protect your ears.


Loudness and frequency of sound

Sound is produced by pressure changes in the ear. The apparent loudness that we identify to a sound varies not only with the sound pressure but also with the frequency.

To put it into more literal terms, loudness can be measured by decibels, and the louder the sound is, the more harm it can do to a person’s ear.

Frequency refers to the atmospheric pressure periodically, and the number of pressure variations per second. The higher the frequency, the more high-pitched a sound is perceived. For example, a sound produced by a drum is lower-pitched, whereas a sound produced by a whistle is higher-pitched.


Occupational deafness

Occupational deafness is damage to the inner ear from noise or vibrations due to certain types of jobs. It can be temporary or permanent hearing loss.

Causes of occupational deafness can often be, the person being exposed to high levels of noises for a long period of time. Over time, repeated exposure to these loud noises will cause hearing loss.

In most cases, sounds above 80 decibels may cause vibrations intense enough to damage the inner ear. This is much more likely to happen if the sound continues for a long time.

Below are some loud noises to give you an indication:

-         A large truck/motorcycles passing by (90 decibels)

-         Rock music concerts (100 decibels)

-         A jackhammer/engine/heavy machinery (120 decibels)

-         A jet engine/airplane (130 decibels)

Therefore, choosing the correct hearing protector is crucial if your work consists of high levels of noises.


Situational: Airport & Hunting /Shooting

Occupational deafness often correlates directly with the person’s job and working environment. Since occupational deafness often occurs when the person is exposed to high levels of noises for a long period of time, the working environment has the most effects on a person’s hearing.

An obvious working environment that exposes workers to very high levels of noises is the airport. Airport workers, especially those working on the ground that are always close to the airplanes taking off, must wear hearing protection to protect their ears, because even when you stand 100 feet away from the airplanes, the noise the airplanes generate is among the loudest noise a person can experience.

Another situation where a person is exposed to high levels of noises are during hunting or shooting sessions. This may happen less in Hong Kong, but it is still a major cause of hearing loss. When a person is aiming with a gun, the gun is very close to the ears, and when the trigger is being pulled, the sound it generates is also among the loudest noise, especially when the gun is so close to the ears, so wearing an ear protector is very important in this situation too!