CAOHC Hearing Protection Devices 2 — Questions and Answers
Question 1: What are the three main categories of hearing protection devices?
- Earplugs, earmuffs, and semi-insert (canal cap) devices (Correct answer)
- Earplugs, helmets, and face shields
- Active noise canceling headphones, earmuffs, and surgical masks
- Custom earplugs, disposable earplugs, and noise barriers
Correct answer: Earplugs, earmuffs, and semi-insert (canal cap) devices
The three main categories are earplugs (inserted into the ear canal), earmuffs (covering the entire ear), and semi-insert devices (sealed against the canal entrance).
Each category has advantages: earplugs offer high attenuation and PPE compatibility; earmuffs are easy to don/doff and visible for compliance; canal caps are convenient for intermittent exposure.
Question 2: What is the OSHA requirement for hearing protector attenuation adequacy?
- Protectors must reduce exposure to at least 90 dBA, or 85 dBA for employees with an STS (Correct answer)
- All protectors must have an NRR of at least 25 dB
- Protectors must reduce noise to 70 dBA or below
- No specific attenuation standard exists under OSHA
Correct answer: Protectors must reduce exposure to at least 90 dBA, or 85 dBA for employees with an STS
OSHA requires attenuation to at least 90 dBA for general HCP participants and to 85 dBA for employees with an STS.
Per 29 CFR 1910.95(j)(2), protectors must achieve these levels. If an employee protector does not achieve required attenuation, the employer must provide a more effective one.
Question 3: What factors should be considered when selecting hearing protectors?
- Noise level, frequency spectrum, PPE compatibility, communication needs, comfort, and work environment (Correct answer)
- Only the highest NRR available
- Price per unit is the sole factor
- Worker preference without any technical evaluation
Correct answer: Noise level, frequency spectrum, PPE compatibility, communication needs, comfort, and work environment
Selection requires evaluating noise characteristics, PPE compatibility, communication requirements, comfort, hygiene, durability, and environmental conditions.
No single protector is optimal for all situations. Octave band data helps match protector attenuation to the noise. Individual ear anatomy means some workers need multiple options.
Question 4: How does temperature and humidity affect hearing protector compliance?
- Hot and humid conditions increase perspiration under earmuffs, reducing comfort and consistent wear (Correct answer)
- Temperature and humidity have no effect
- Cold temperatures cause foam earplugs to provide more attenuation
- Humid conditions improve the seal of all protector types
Correct answer: Hot and humid conditions increase perspiration under earmuffs, reducing comfort and consistent wear
Hot, humid environments cause increased sweating under earmuff cushions, leading to discomfort and reduced compliance.
Solutions include earplugs (which do not trap heat), gel-filled cushions, hygiene covers, and ventilated hard hat-mounted earmuffs. Understanding environmental challenges is essential for selection.
Question 5: What is the difference between NRR and NRR(SF) ratings?
- NRR uses trained subjects for testing; NRR(SF) uses naive subjects for more realistic estimates (Correct answer)
- They are identical ratings from different manufacturers
- NRR is for earplugs only and SNR is for earmuffs only
- NRR is a US metric while SNR is used only in Asia
Correct answer: NRR uses trained subjects for testing; NRR(SF) uses naive subjects for more realistic estimates
The NRR uses trained, supervised subjects and tends to overestimate. The NRR(SF) uses naive, unsupervised subjects for more realistic values.
NIOSH recommends derating the traditional NRR: 50% for earmuffs, 50% for formable plugs, 70% for pre-molded plugs, to better approximate real-world performance.
Question 6: How should an employer handle an employee who refuses to wear hearing protectors?
- Enforce through progressive discipline while simultaneously addressing specific concerns about comfort or fit (Correct answer)
- Allow the employee to work without protection
- Immediately terminate the employee
- Assign the employee to a different job without requirements
Correct answer: Enforce through progressive discipline while simultaneously addressing specific concerns about comfort or fit
The employer must enforce protector use while actively addressing the worker specific concerns causing resistance.
Steps include investigating the reason, resolving underlying issues with different protector types, educating about consequences, and applying progressive discipline if resistance continues.
CAOHC Hearing Protection Devices 2
What are the three main categories of hearing protection devices?