Hearing Protector Selection Criteria

Provision of Hearing Protectors

Department Supervisors must provide employees who are exposed to excessive noise with suitable hearing protectors. 

Hearing protectors issued to employees shall be recorded in Issue of Personal Protective Equipment (PPE) Record 

Before hearing protectors are issued to the affected employees, the need for their use and limitations should be fully explained

Types of Hearing Protectors

Ear muffs

Table 3: Advantages and disadvantages of ear muffs

Ear plugs

Table 4: Advantages and disadvantages of ear plugs

 

Selection of Hearing Protectors

Hearing protectors provide about 15 dB(A) reduction of reliable protection for majority  of the workforce (about 84%).  Therefore, employees who are exposed to a noise level of above 100 dB(A) while wearing hearing protectors can still incur substantial hearing loss over a lifetime since the protected ears would still be exposed to a noise level higher than 85 dB(A).

When selecting hearing protectors, one must know the noise exposure level and the noise reduction rating (NRR) of the hearing protectors, which is the expected level of noise reduction in the ears when they are properly worn. The higher the NRR, the higher is the attenuation for a specific ideal situation.  The NRR is provided by the manufacturers.

Exposed Noise Level (ENL) for employees can be determined through the following:

-For noise levels in dB(A), the effective A-weighted ENL = sound
 pressure level in dB(A) – (NRR – 7)
-For noise levels (octave bands) in dBC, ENL = sound pressure
 level in dBC – (NRR)
-Ear muffs will be a preferred choice over ear plugs in unclean
 working conditions, where there is a risk of infection to the user.
-Ear plugs are recommended in work areas with high temperature
 and humidity
-The selected hearing protectors should be able to reduce the noise
  level to below the Permissible Exposure Limit (PEL)  of 85 dB(A)
  at the ear. 
-Employees should not be issued hearing protectors with
 unnecessarily high attenuation as it may bring about
 communication difficulties and cause isolation.  Such problems
 caused by over protection can result in employees refusal to wear
 the hearing protectors. 
-A suitable hearing protector should reduce the noise level to
 between 5 and 10 dB(A) below the PEL
-Before hearing protectors are issued to the employees, they should
 be consulted to determine if they are suffering from any medical
 conditions related to the ears, such as irritation of the ear canal. In
 which case, they should avoid the use of earplugs.
-The EHS Officer / Manager shall recommend suitable hearing
  protectors to Department Supervisors whose work areas /
  processes have been identified with excessive noise hazards.

Proper Wearing of Hearing Protectors

Employees should be adequately trained in the correct wearing of the hearing protectors to ensure that they receive the maximum protection available

For re-usable earplugs, pull the ear lobe backwards and upwards, then insert. This would ensure a proper fit. The disposable foam earplugs have to be rolled before inserting into the ears. The ear cup of the ear muffs should cover the ear lobes completely. (See Figure 2 below)

Maintenance of Hearing Protectors

For personal hygiene, re-usable earplugs must be washed frequently in warm, soapy water and left to dry before keeping.

Ear muffs may be cleaned with disposable alcohol swipes or wiped down with damp cloth and wiped dry.

Hearing protectors should be checked regularly and replaced when necessary. They should be kept in a clean place when not in use.

Supervisors shall maintain enough stock of earplugs to ensure their staff can replace damaged earplugs as soon as possible.

Hearing Protector Areas

Employees who enter areas where hearing protector signs are to put up are required to wear hearing protectors when working in such areas. 

Training and education

The EHS Officer / Manager shall be responsible for carrying out HCP training at least once every year for employees exposed to excessive noise and within three months of job commencement for new employees. Training program should include:

-adverse effects of noise on hearing,

-purpose and benefits of HCP,

-HCP policies,

-purpose of hearing protectors,

-advantages, disadvantages and attenuation of the various hearing protectors,

-instructions on the proper selection, fitting, use and maintenance of hearing protectors,

-importance of the consistent wearing of hearing protectors,

-purpose and procedures of audiometric testing, including pre-test instructions, and

-explanation of the audiometric results and the preventive measures.

 

Training records shall be maintained 

The EHS Officer / Manager shall also maintain a copy of training records for at least 10 years.

Audiometric examinations

-Audiometric examinations can help to detect early stage of hearing loss and is an important part of the HCP.

-HR shall arrange annual audiometric examination for staff identified by the WSH Officer as exposed to / potentially  exposed to excessive noise. 

-HR shall keep audiometric records for at least 10 years from the date of examination.

-No later than 10 days upon receipt of a written diagnosis by a registered medical practitioner diagnosing employees suspected to be suffering from NIHL, HR and WSH Officer shall submit a report to the Commissioner for WSH.

 

Documented information

As NIHL occurs gradually upon exposure to excessive noise, complete documentation can aid in retaining information needed for the evaluation on the effectiveness of the preventive and control measures. 

The following types of records shall be maintained by the HCP Administrator:

-HCP Policy Statement,

-Records of noise monitoring made available for at least 10 years from the date of monitoring,

-Records of risk assessment kept available for at least three years,

-Noise Control Plan kept available for at least three years,

-documentation of noise control solutions,

-documentation to show the issue, fitting and training of hearing protectors,

-documentation of employee’s training,

-records of audiometric calibration data (for audiometric technician),

-records of audiometric examinations kept for at least five years from the date of examination (kept by HR),

-records of follow up actions in response to employees’ hearing threshold shifts, and

-records of program evaluation 

Program Evaluation

-Evaluation of HCP is required to determine the effectiveness of the programme in preventing NIHL and to identify any gaps with specific elements for immediate corrective actions to be taken.

-The evaluation should be performed on a periodic basis to ensure continual improvements and involves a team effort.

-HCP administrator shall initiate the HCP evaluation with a aid of Appendix B – Hearing Conservation Program Evaluation
 Checklist