Environmental, Health and Safety Services

Hearing Protection Devices

Availability and Provision

Engineering and administrative controls are the most effective and preferred method to prevent noise-induced hearing loss. In many cases, however, prevention methods also include the use of Hearing Protection Devices (HPDs). These simple and inexpensive devices can prevent noise-induced hearing loss, but as with all types of Personal Protective Equipment (PPE), their effectiveness depends upon proper:

  • Selection,
  • Fitting,
  • Education, and
  • Proper and consistent uses when exposed to noise

EHS recommends appropriate HPDs based on noise attenuation requirements. A variety of appropriate types of protectors must be made available to employees. The employee's department must pay for and continue to provide any required HPD to the employee at no cost. Employees are responsible for wearing required HPD and supervisors are responsible for enforcing consistent HPD use.


The two mostly commonly used types of HPDs at Virginia Tech are ear plugs and ear muffs. An ear plug is inserted into the ear canal to reduce the amount of noise that reaches the ear via that route. An ear muff is worn over the ear to reduce the amount of noise the ear receives via the ear canal. These HPDs can not eliminate all the noise reaching the ear as noise can take many routes into the ear as illustrated below.

Plug Attenuation

Muffle Attenuation

To prevent noise-induced hearing loss, HPDs must reduce noise exposure to time-weighted average levels of 90 dBA or below, or to 85 dBA or below for those workers who have suffered a standard threshold shift.