1. Earplugs
Earplugs that meet comfort requirements:
- Made of soft materials
- Expand uniformly and fully conform to the ear canal
- Available in various shapes and sizes to suit different users
- Smooth surface that prevents dirt accumulation and ear canal contamination
Earplugs that do not meet comfort requirements:
- Made of hard materials that can cause localized pressure, leading to ear pain and headaches
- Expand too quickly, pressing against the ear canal and leaving gaps
- Have a single shape and size, making them unsuitable for different users
- Large surface pores that easily trap dirt, leading to secondary ear canal contamination
2. Earmuffs
Earmuffs that meet comfort requirements:
- Compact structure and lightweight design to reduce fatigue during prolonged wear
- Conform to the ear’s contour, evenly distributing pressure
- Equipped with AFC technology, making the earmuff cups lighter and thinner while maintaining the same NRR value
Earmuffs that do not meet comfort requirements:
- Heavy and bulky, which can cause neck strain
- Create localized pressure points around the ear bones, leading to discomfort over long-term use
- Lack AFC technology
Selection Methods
| Type | Foam Earplugs | Reusable Earplugs | Banded Earplugs | Earmuffs |
|---|---|---|---|---|
| Environment | ||||
| Long-term wear required | ✓ | ✓ | ✗ | ✗ |
| Frequent putting on and taking off | ✗ | ✗ | ✓ | ✓ |
| Personnel Requirements | ||||
| Exposure to liquid splashes or dirty environments | ✗ | ✗ | ✗ | ✓ |
| Employees with ear canal conditions | ✗ | ✗ | ✓ | ✓ |
| Visitors | ✗ | ✗ | ✓ | ✗ |
Wearing and Testing Methods
1) Wearing method for foam earplugs
- Roll: Wash and dry hands, then roll the entire earplug into a smooth, cylindrical shape.
- Pull: Reach over the head with one hand and gently pull the top of the ear upward and backward.
- Insert: Fully insert the earplug into the ear canal and hold it in place until it expands to fill the ear canal, then release.
2) Visual inspection method for foam earplugs
- If worn correctly, the end of the earplug should not extend beyond the tragus (the small protrusion at the ear canal entrance).
3) Acoustic test method for foam earplugs
- Cover both ears with your hands and then release. If worn correctly, the earplugs should significantly reduce noise, with only a minimal difference in perceived sound.
4) Wearing method for reusable earplugs and one testing method
- Hold the earplug stem with one hand while using the other hand to reach over the head and gently pull the ear upward and backward.
- Insert the earplug, ensuring that all flanges (soft wings) are completely inside the ear canal.
- If worn correctly, only the earplug stem should be visible from the front.
5) Acoustic test method for reusable earplugs
- Cover both ears with your hands and then release. If worn correctly, the earplugs should significantly reduce noise, with only a minimal difference in perceived sound.
6) Wearing method for earmuffs
- Place the earmuffs over the ears.
- Adjust the headband length up or down as needed.
- Ensure the ear cushions fit snugly against the head.
Importance of Proper Wearing
- Incorrect wearing reduces the expected noise reduction effect.
- Wearing time affects the noise reduction rating (NRR) of hearing protection products.
Example:
A user working in a 100 dB environment for 8 hours wears earplugs with an NRR of 30. If the user removes the earplugs for a period, exposing their ears to the noise environment unprotected, the effective NRR cannot be guaranteed, leading to potential hearing damage.
Explanation:
Even brief exposure to high noise levels without hearing protection can quickly negate the protective effects of prolonged proper use, ultimately causing hearing damage.
Conclusion
- Workers must be trained to correctly wear hearing protection products and learn self-check and peer-check methods.
- According to the “Hearing Protection Regulations for Industrial Workers,” employees exposed to an equivalent noise level of ≥85 dB for an 8-hour workday must undergo regular hearing protection training.
- In environments with noise levels of ≥85 dB, hearing protection products must be worn continuously without interruption.
- If there is a special situation requiring removal of hearing protection, the worker must first leave the noisy environment. The hearing protection product should only be removed once the worker has moved to an environment with noise levels below 85 dB.
