Noise Reduction and Hearing Conservation 170

This class explains the causes of hearing damage and describes how to avoid exposure to excessive noise.

Class Details

Class Name:
Noise Reduction and Hearing Conservation 170
This class explains the causes of hearing damage and describes how to avoid exposure to excessive noise.
Number of Lessons:
Additional Language:
Related 2.0 Class:
Noise Reduction and Hearing Conservation 121

Class Outline

  • Objectives
  • The Importance of Hearing Conservation
  • Sound vs. Noise
  • How Noise Affects Ear Anatomy
  • Types of Hearing Loss: Conductive
  • Types of Hearing Loss: Sensorineural
  • Hearing Conservation Program
  • Measuring and Monitoring Noise Exposure Levels
  • Engineering Changes and Administrative Controls
  • Hearing Testing, Monitoring, and Record Keeping
  • Hearing Protection Requirements
  • Types of Hearing Protection
  • Employee Training
  • Risks and Benefits of Hearing Protection
  • Summary


  • Describe the importance of hearing conservation.
  • Distinguish between sound and noise.
  • Describe how noise affects ear anatomy.
  • Describe conductive hearing loss.
  • Describe sensorineural hearing loss.
  • Describe OSHA’s criteria for requiring employers to implement a hearing conservation program.
  • Identify ways that employers measure and monitor noise exposure levels.
  • Describe engineering changes and administrative controls for hearing conservation.
  • Define audiometric testing.
  • Describe OSHA’s requirements for hearing protection.
  • Distinguish among the different types of hearing protection.
  • Describe the types of hearing conservation training that employers must provide their employees.
  • Describe the risks and benefits of hearing protection.

Job Roles


  • MSSC Safety


Vocabulary Term Definition
acoustic wave The result of a vibrating source, such as a machine motor or human vocal cords, disturbing the air.
administrative control Modifications to areas like staffing, schedules, or procedures to reduce employees' exposure to noise.
air pressure A type of force that air exerts over a certain area due to its motion.
audiologist A person who is trained to perform hearing testing and evaluate hearing loss.
audiometric testing A series of hearing tests used to measure hearing over time and detect any changes that may have occurred.
baseline audiogram A hearing test used to determine an employee's beginning level of hearing ability.
chronic noise Unwanted sound that occurs continuously or over and over again with little interruption.
cilia Tiny hair-like projections that move according to pressure changes. The cilia's movements are perceived by the hair cells as sound.
conductive hearing loss Loss of sound perception associated with the outer ear that may be medically or surgically corrected. Causes of conductive hearing loss include infection, excess wax, or a blow to the head.
decibel A unit of measurement of the intensity of a sound wave.
dosimeter A measuring instrument that measures total noise exposure over time. A dosimeter is often worn by the employee on the shoulder to measure individual noise exposure.
ear canal The long portion of the middle ear that connects the outer ear to the inner ear.
eardrum A vibrating membrane that stretches across the inner end of the ear canal.
earmuffs A type of personal protective equipment that covers the entire outer ear. Earmuffs consist of two ear coverings connected by a band.
earplug A common type of personal protective equipment that is placed into the ear canal to prevent excessive noise from entering the ear.
engineering change Modifications to machinery and other components to prevent or reduce noise production. Enclosing a machine motor to reduce the amount of noise entering the environment is an example.
hair cells Sensory cells within the inner ear that support the cilia and transform the mechanical energy of sound waves into nerve impulses.
hazardous noise Unwanted sound that is capable of harming hearing. Hazardous noise is usually loud, but some high-pitched noises can harm the ears without being heard.
hearing conservation Different measures taken to reduce exposure to noise, such as wearing hearing protection.
hearing conservation program A formal program that consists of several components intended to prevent worker hearing loss. An HCP must include noise evaluations, hearing testing, and hearing protection.
hearing loss A reduced ability to hear sounds. Noise exposure and heredity are two of the causes of hearing loss.
hearing protection A type of personal protective equipment specifically designed to prevent hearing damage. Earplugs are the most common form of hearing protection.
heredity The transmission of characteristics from one generation to the next, such as blue eyes or skin color. Hearing loss can be an inherited characteristic.
inner ear The interior portion of the ear that transforms the mechanical movement of vibration on the eardrum to nerve impulses. These impulses travel to the brain where they are perceived as sounds.
middle ear The air-filled central portion of the ear that converts and amplifies waves in the ear canal into a vibration in the eardrum.
nerve impulses Electrical signals that send and receive information to and from the brain.
noise Any unwanted sound. Noise can be loud or soft.
occupational hearing loss A reduced ability to hear sounds that is often caused by exposure to loud noise in the workplace.
outer ear The external portion of the ear that modifies the sound waves in the environment and directs them toward the eardrum.
pre-formed earplug A type of earplug that is individually molded and fitted by a professional.
sensorineural hearing loss Loss of sound perception associated with the inner ear that is irreversible. Causes of sensorineural hearing loss include heredity, chronic noise exposure, and certain medications.
silicone rubber A soft, pliable material often used in medical devices.
single-use earplug Disposable earplugs that are often made of waxed cotton, foam, or silicone rubber.
sound The physical phenomenon that stimulates our sense of hearing. Sound is an acoustic wave that results when a vibrating source disturbs the air.
sound-level meter A measuring instrument used to determine the loudness of sounds. Sound-level meters generally measure noise in an area.
time-weighted average A measure of noise exposure that is an average of varying levels of noise experienced in a given eight-hour workday.
vocal cord One of two small bands of muscle in the throat that vibrate to produce the human voice.
volume-reducing earplugs A newer variety of earplug often worn by musicians and others who must reduce the sound volume in their environment without losing sound quality.