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Managing Noise and Preventing Hearing Loss

Noise as a Hazard​

Excessive noise exposure causes permanent, irreversible hearing loss. Construction work involves many noise-producing activities making hearing protection essential.

Common Construction Noise Sources:

  • Power tools (grinders, saws, nail guns, jackhammers)
  • Heavy plant and equipment (excavators, loaders, compactors)
  • Concrete cutting and drilling
  • Impact tools (jackhammers, post drivers)
  • Generators and compressors

[!warning] Permanent Damage Noise-induced hearing loss is permanent and cannot be reversed. Prevention is the only solution.

Exposure Standards​

WHS Regulation 56:

  • LAeq,8h = 85 dB(A) (8-hour time-weighted average)
  • LC,peak = 140 dB(C) (peak noise level)

What this means:

  • Average noise over 8 hours must not exceed 85 dB(A)
  • Instantaneous peak noise must not exceed 140 dB(C)

Indicative Noise Levels:

  • Normal conversation: 60 dB(A)
  • Busy traffic: 80 dB(A)
  • Lawn mower: 90 dB(A)
  • Chainsaw: 110 dB(A)
  • Jackhammer: 120 dB(A)

[!tip] Conversation Test If you need to raise your voice to talk to someone 1 meter away, noise levels are likely approaching or exceeding 85 dB(A).

Who Has Duties?​

PCBUs​

Must:

  • Identify noise hazards
  • Assess risks of hearing damage
  • Eliminate or minimize noise exposure
  • Ensure exposure below standards
  • Provide hearing protectors if engineering controls insufficient
  • Provide information and training
  • Conduct audiometric testing where required

Designers, Manufacturers, Suppliers​

Must:

  • Design plant to minimize noise generation
  • Provide noise emission data
  • Include noise control features in equipment

Risk Management Process​

1. Identify Hazards​

Indicators of Noise Hazard:

  • Need to shout to be heard 1 meter away
  • Ringing ears or muffled hearing after work
  • Complaints from workers about noise
  • Noise complaints from neighbors/public

Review:

  • Manufacturer specifications for equipment (noise ratings)
  • Previous noise assessments
  • Incident reports

2. Assess Risks​

When Noise Assessment Required:

  • Uncertain if exposure exceeds standards
  • To verify control effectiveness
  • After changes to work processes or equipment

Who Conducts Assessment:

  • Competent person (occupational hygienist, acoustician)
  • Uses calibrated sound level meters
  • Personal noise dosimeters for individual exposure

3. Control Risks: Hierarchy of Control​

Level 1: Elimination

  • Modify process to not require noisy equipment
  • Example: Use mechanical fixing instead of impact tools where possible

Level 2: Substitution

  • Replace with quieter equipment or methods
  • Example: Electric tools instead of pneumatic tools
  • Example: Hydraulic splitters instead of jackhammers

Level 2: Isolation

  • Separate workers from noise source
  • Relocate noisy equipment away from workers
  • Establish noise exclusion zones
  • Remote operation of noisy plant

Sound reduction by distance Figure: Sound is reduced by about 6 dB for each doubling of distance

Level 2: Engineering Controls

Noise Reduction at Source:

  • Install mufflers on exhaust systems
  • Use damping materials on vibrating surfaces
  • Maintain equipment (worn parts increase noise)
  • Enclose noisy equipment in acoustic barriers

Example of engineering noise controls Figure: Examples of noise control measures (enclosures, isolation)

Example: Fit compressor with acoustic enclosure and muffled exhaust.

Barriers and Screens:

  • Acoustic barriers between noise source and workers
  • Sound-absorbing materials in enclosed spaces

Vibration isolation Figure: Isolating machine vibration from structure

Maintenance:

  • Regular maintenance reduces noise (worn bearings, loose parts)
  • Replace damaged mufflers and acoustic seals

Level 3: Administrative Controls

  • Limit time workers exposed to high noise
  • Job rotation to reduce individual exposure
  • Restrict access to high-noise areas
  • Schedule noisy work when fewer workers present

Level 3: Personal Protective Equipment

[!important] Last Resort Hearing protection is least effective control. Use only after higher controls implemented.

Types of Hearing Protection:

Earplugs:

  • Foam, pre-molded, or custom-fitted
  • Inserted into ear canal
  • Typical reduction: 20-30 dB

Earmuffs:

  • Cushioned cups over ears
  • Typical reduction: 20-35 dB
  • More visible (easier to check compliance)

Selection:

  • Must provide sufficient attenuation to reduce noise below 85 dB(A)
  • Consider comfort (workers more likely to wear)
  • Hygiene (clean, replace when worn)

Limitations:

  • Only effective when worn correctly and consistently
  • Gaps or poor fit reduce effectiveness dramatically
  • Workers may remove during breaks but still in noisy area

4. Maintain and Review​

  • Inspect and maintain noise control equipment
  • Monitor noise levels after changes
  • Check hearing protector condition
  • Review after workers report hearing issues
  • Conduct audiometric testing

Audiometric Testing​

When Required (WHS Reg 58): If worker exposed to noise exceeding standards and at risk of hearing loss.

What it Involves:

  • Baseline hearing test (before exposure)
  • Periodic re-testing (annually for high-risk, every 2 years otherwise)
  • Conducted by qualified person (audiologist, audiometrist)
  • Identifies early signs of hearing loss

Benefits:

  • Detects hearing loss early
  • Allows intervention before significant damage
  • Confirms control measures working

Worker Rights:

  • Access to test results
  • Confidential health information
  • No cost to worker

Practical Construction Example​

Scenario: Concrete cutting for service trenches

Hazard Identification​

  • Petrol-powered concrete saw generates 110 dB(A)
  • Workers cutting for several hours per day
  • Other workers in vicinity

Risk Assessment​

  • High risk: Exposure well above 85 dB(A)
  • Operator and nearby workers affected

Controls Implemented​

Engineering:

  • Selected electric saw (quieter than petrol, 95 dB(A))
  • Acoustic barrier erected around cutting area
  • Work during day (fewer workers on site)

Isolation:

  • Exclusion zone 5 meters from saw
  • Only operator and one offsider in zone
  • Signage indicating high-noise area

Administrative:

  • Limit continuous cutting to 1-hour blocks
  • Job rotation among qualified operators
  • Advance notice to other trades (relocate if possible)

PPE:

  • Class 5 earmuffs for operator (30 dB reduction)
  • Earplugs for offsider (25 dB reduction)
  • Hearing protection mandatory in exclusion zone

Monitoring​

  • Noise assessment confirmed exposure <85 dB(A) with controls
  • Audiometric testing arranged for regular operators

Other Noise Effects​

Ototoxic Substances​

Exposure to certain chemicals (ototoxic substances) can result in hearing loss or exacerbate the effects of noise.

  • Solvents: Toluene, xylene, styrene
  • Heavy Metals: Lead, mercury
  • Asphyxiants: Carbon monoxide

Control measures must consider both noise and chemical exposure.

Tinnitus​

Ringing, buzzing, or whistling in ears. May be temporary or permanent.

Communication and Safety​

High noise:

  • Impairs communication
  • Prevents hearing warning signals
  • Masks approaching vehicles/equipment
  • Increases accident risk

Controls:

  • Visual warning signals in high-noise areas
  • Hand signals for communication
  • Flashing lights on mobile plant

Stress and Fatigue​

Prolonged noise exposure causes:

  • Increased stress levels
  • Mental fatigue
  • Reduced concentration
  • Lower productivity

Information and Training​

Workers must be informed about:

  • Risks of noise exposure and hearing loss
  • Noise levels in their work areas
  • How to use and maintain hearing protection
  • How to identify when noise controls not working
  • Audiometric testing requirements
  • Reporting hearing changes