Hierarchy of Controls for Managing Noise Hazards

Effectively managing occupational noise hazard is a daily activity that involves everyone on the worksite.? Regardless if your work environment is in the general industry or construction industry, the principles of managing noise hazards are the same.? Sometimes easy to accomplish, sometimes not so easy.

Prevention of noise as an occupational hazard can be managed in three ways based upon the Hierarchy of Controls (see below).? This article will focus later on personal protective equipment (lease effective method of the hierarchy of controls) since it is the most common approach to mitigation noise hazards in the workplace.

Hierarchy of Controls

Engineering controls means controlling the hazard at the source.? It includes a physical change to the workplace.? Engineering controls is accomplished with installation of proper equipment or re-designing tools and equipment.

Administrative controls are aimed at reducing employees exposure to noise hazards, but they do not remove the hazard.? This control method requires the worker and employer to do something.? Written work procedures and policies is an example of an administrative control.? Another example would include schedule changes such as rotating employees in high noise areas.? Training employees on occupational noise hazards, the consequences of the hazards along with describing the operational controls to minimize or eliminate the hazard would be considered an administrative control.

Personal Protective Equipment (PPE) is commonly known as the? control of ?last resort?.?? This last resort includes workers to wear something to minimize noise hazards to an acceptable level of risk.? Personal protective equipment for noise hazards include inserts, semi-aural earplugs and ear muffs.

All hearing protectors are designed to reduce the intensity (loudness) of noise to the inner ear.

Hearing protection devices are selected according to:

  • Employee comfort
  • Level of noise exposure
  • NRR of device
  • Type of work being performed
  • Environmental condition

Employee may select hearing protection from a variety of suitable hearing protectors provided by employer.

Let?s now talk about the advantages and disadvantages of each.

1)? Ear Muffs


  • More protection at higher frequencies than earplugs
  • Various NRRs available
  • Durable, long lasting
  • Can be fitted on hard hat
  • Reusable

Ear Muffs


  • Higher cost
  • Eye glasses can interfere with ear muff seal
  • May be uncomfortable in hot environments
  • Must be cleaned before use by another worker

2)? Insert Plugs


  • More protection at lower frequencies than muffs
  • Various NRRs available
  • Inexpensive; disposable
  • Can be custom molded for individual worker
  • Reusable plugs are available Disadvantages

Insert Plugs


  • Hands must be cleaned before inserting earplugs
  • Improper insertion reduces noise reduction rating value

3) Semi-Aural (sometimes called ear caps)


  • Various NRRs available
  • Easy to insert
  • May be used several times
  • Ideal for people going in and out of noisy areas



  • Improper insertion reduces effectiveness
  • More expensive than ear plugs
  • Typically have lower NRRs than plugs or muffs

In closing, there are important factors about utilizing personal protective equipment to mitigate occupational noise hazards. ?First, employers must ensure proper initial fitting of personal protective equipment.? This includes demonstration on how to use inserts, semi-aural earplugs and ear muffs (depending on employer decision of what to supply for workers).? In addition, the employer must supervise the correct use of hearing protectors as well as ensure workers understand how to clean and properly store their hearing protectors and when to replace them.

Sometimes the last resort is often the first resort when it comes to managing occupational noise.? When doing so, it is important for both employer and worker to understand the pros and cons of using personal protective equipment.? Hopefully, this article helped shed light on that.