Occupational noise-induced hearing loss (ONIHL) is one of the most preventable occupational diseases, yet continues to affect ~1 in 3 Australians. In 2017 alone, ONIHL associated healthcare and productivity loss cost Australian businesses a combined $33.3 billion AUD.

ONIHL commonly occurs in three major ways:

1. Short-term exposure to a sudden loud noise exceeding 140 decibels (dB)
2. Long-term exposure (continuous 8 hours) to moderate noise exceeding 85 dB
3. Long-term exposure to chemicals which damage internal ear structures in combination with moderate-to-loud noises

Industries most at risk of ONIHL

Workers in industries that consistently utilise heavy machinery (e.g. bulldozers, cement mixers, compressors, cutting machinery, drill machines, fracturing equipment, generators, haul trucks, jackhammers, milling equipment and well pumps) are most at risk of developing ONIHL. These industries include:

• Construction
• Manufacturing
• Mining
• Oil and Gas

Railway workers who operate locomotive diesel engines, horns and brakes or those who are positioned at railroad classification yards are also at high risk of developing ONIHL.

Effects of ONIHL on workers and businesses

Workers with impaired hearing may experience:

• Difficulty communicating
• Tinnitus (a continuous ringing in the ears)
• Insomnia (inability to fall asleep or remain asleep)
• Mental decline (hearing loss can place the brain under more stress when processing incoming information)
• Social isolation which can contribute to depression and anxiety

Businesses with workers experiencing ONIHL often see:

• Decreased employment – workers may no longer meet the safety requirements for their roles
• Decreased productivity – affected workers may be experiencing higher levels of stress, frustration with communication, difficulty concentrating and lower levels of motivation
• Increased healthcare/productivity loss costs

4 tips for preventing ONIHL in the workplace

Understand the different types of personal protective equipment

The most effective protective equipment prevents hearing damage without over-protection (e.g. unnecessarily blocking critical workplace communications that may increase other workplace dangers).

In-ear protection

Foam earplugs

• Typically reduce noise by 30–33 dB
• Conform to the unique shape of a worker’s ear, totally blocking the ear canal with an airtight seal
• Affordable
• Are often one-time use

Silicone earplugs

• Typically reduce noise by 20–26 dB
• Conform to the unique shape of a worker’s ear
• More durable than foam – can be cleaned and reused

Over-ear protection

Canal caps

• Typically reduce noise by ~25 dB
• Only close the ear opening and do not extend into the ear canal
• Ideal for situations where protection has to be inserted/removed frequently

Earmuffs

• Typically reduce noise by ~30 dB
• One size fits all – can be adjusted to fit snugly around a worker’s head
• Does not directly block the air canal
• Source of warmth in cooler environments

Provide workers with regular audiometric testing

Monitoring ear health is essential for early detection of ONIHL, informs businesses of the effectiveness of their mitigation strategies and helps prevent further ear health deterioration.

By 31 March 2024, the states of NSW, QLD and WA will all require any persons conducting a business or undertaking (PCBU), where employees must wear personal protective equipment against short-term exposure to noise exceeding 140dB and long-term exposure (continuous 8 hours) to noise exceeding 85 (or 90 in WA) dB, to provide (baseline) occupational noise testing:

• Within 3 months of a worker initiating employment
• At least every 2 years thereafter(or more frequently if required) for the duration of employment

Occupational noise testing differs from screening audiometry tests most PCBUs conduct prior to hiring a candidate.

Check out our new and improved comprehensive guide and free fact sheet detailing the differences between all our available audiometric tests. We also recommend following up with your specific state's legislation to ensure your existing employees comply with all audiometric requirements. 

Alter the workplace landscape to reduce the risk of noise exposure

• Encourage employees to report malfunctioning or poorly-maintained heavy machinery. Oiled and well-maintained machinery tends to produce less noise
• Control worker rotation in extremely noisy areas so that no one individual is consistently exposed to noise
• Plan the layout of the worksite such that activities generating the highest noise pollution are located in open areas and far away from break areas. Site Risk Assessments can be extremely helpful in optimising the workplace layout

Control exposure to ototoxic substances 

Long-term exposure to ototoxic substances (chemicals that cause ear damage) can increase ear sensitivity to loud noise.

The three major classes of ototoxic substances include:

• Asphyxiants e.g. carbon monoxide and hydrogen cyanide
• Heavy metals e.g. arsenic, chromium, lead and mercury
• Solvents e.g. butanol and carbon disulphide

Where possible, employers should endeavour to replace such substances with safer substitutes, ensure the workplace has adequate ventilation systems and provide appropriate training to staff on how to best recognise and manage chemical hazards.