NEBOSH CC Dust & Noise in Construction 3 — Questions and Answers
Question 1: What is the Exposure Limit Value (ELV) for noise that must not be exceeded under the Control of Noise at Work Regulations 2005?
- 87 dB(A) daily or weekly average, taking account of any hearing protection worn (Correct answer)
- 85 dB(A) without hearing protection
- 90 dB(A) with any hearing protection
- 80 dB(A) without hearing protection
Correct answer: 87 dB(A) daily or weekly average, taking account of any hearing protection worn
The ELV for noise is 87 dB(A) as a daily or weekly average, taking into account the attenuation provided by hearing protection. This is the absolute limit that must not be exceeded, even with hearing protection worn.
Question 2: What type of hearing loss is caused by prolonged exposure to excessive noise?
- Noise-induced hearing loss (NIHL), which is permanent and irreversible (Correct answer)
- Temporary threshold shift that recovers with rest
- Conductive hearing loss that can be treated surgically
- Tinnitus that always resolves after leaving the noisy environment
Correct answer: Noise-induced hearing loss (NIHL), which is permanent and irreversible
Noise-induced hearing loss (NIHL) is caused by prolonged exposure to excessive noise levels. The damage to hair cells in the cochlea is cumulative, permanent and irreversible. There is no medical treatment that restores lost hearing.
Question 3: What is tinnitus?
- A persistent ringing, buzzing or hissing sound in the ears not caused by an external source (Correct answer)
- A temporary loss of hearing after a single loud noise event
- A condition that always accompanies noise-induced hearing loss
- An infection of the ear caused by wearing hearing protection
Correct answer: A persistent ringing, buzzing or hissing sound in the ears not caused by an external source
Tinnitus is a condition where a person experiences sounds (ringing, buzzing, hissing, whistling) in the ears or head with no external source. It can be caused by noise damage and may be temporary or permanent. It significantly affects quality of life.
Question 4: Which type of construction equipment typically generates the highest noise levels?
- Pneumatic breakers, angle grinders and disc cutters (Correct answer)
- Electric drills
- Circular saws
- Hand tools
Correct answer: Pneumatic breakers, angle grinders and disc cutters
Pneumatic breakers (jackhammers) and angle grinders are among the loudest tools on construction sites, often exceeding 110 dB(A). These levels can cause permanent hearing damage within a very short exposure time without hearing protection.
Question 5: What hierarchy of controls should be applied to reduce noise exposure on construction sites?
- Eliminate the noise source, substitute with quieter equipment, engineer out the noise, use administrative controls, then PPE (hearing protection) (Correct answer)
- Provide hearing protection immediately without considering other controls
- Only use administrative controls such as job rotation
- Measure noise levels and tell workers to tolerate acceptable levels
Correct answer: Eliminate the noise source, substitute with quieter equipment, engineer out the noise, use administrative controls, then PPE (hearing protection)
The hierarchy for noise control mirrors the general hierarchy: eliminate the source, substitute quieter equipment or processes, engineer controls (enclosures, barriers, damping), administrative controls (rotation, scheduling noisy work when fewer people are present), and finally hearing protection as a last resort.
Question 6: What is the purpose of a 'hearing protection zone' on a construction site?
- An area where noise levels are at or above the upper action value and where wearing hearing protection is mandatory (Correct answer)
- An area where noise is prohibited to protect workers
- A zone where hearing tests are carried out
- An area reserved for noisy plant to separate it from workers
Correct answer: An area where noise levels are at or above the upper action value and where wearing hearing protection is mandatory
A hearing protection zone must be designated where noise levels reach or exceed the UAV of 85 dB(A). All workers and visitors in these zones must wear suitable hearing protection. The zone must be clearly marked with appropriate signs.
NEBOSH CC Dust & Noise in Construction 3
What is the Exposure Limit Value (ELV) for noise that must not be exceeded under the Control of Noise at Work Regulations 2005?