Noise Reduction and Hearing Conservation 121

acoustic filtering earplugs

A newer variety of ear protection that reduces the sound volume in an environment without losing sound quality. Acoustic filtering earplugs, also known as volume-reducing earplugs or noise filtering earplugs, are often used by musicians.

acoustic waves

Acoustic waves are the result of a vibrating source disturbing the air. Acoustic waves cause sound.

administrative controls

Modifications to aspects of a workplace like staffing, schedules, or procedures. Administrative controls reduce employees' exposure to noise.

audiologist

A person who is trained to perform hearing tests and evaluate hearing loss. An audiologist may suggest an employee wear particular hearing PPE depending on the state of the person's hearing.

audiometric testing

A series of hearing tests used to measure hearing over time. Audiometric testing detects any hearing changes that may occur.

baseline audiogram

A hearing test used to determine an employee's level of hearing ability before it is affected by a work environment. A baseline audiogram will detect any hearing deficiencies that already exist for a person.

chronic noise

Unwanted sound that occurs continuously or repeatedly with little interruption. Chronic noise exposure can cause hearing loss.

cilia

Tiny, hair-like projections that move according to pressure changes. Cilia transmit vibrations within the inner ear.

conductive hearing loss

A loss of sound perception that is associated with the outer ear and may be medically or surgically corrected. Causes of conductive hearing loss include infection, excess wax, or a blow to the head.

custom-fit earplugs

A type of hearing protection molded to fit a specific individual’s ears. Custom-fit earplugs, also known as molded earplugs or pre-formed earplugs, are usually professionally made.

decibels

dB. A unit of measurement of the intensity of a sound wave. Decibels measure how loud sounds are.

disposable earplugs

A type of hearing protection that can be thrown away after use. Disposable earplugs, or single-use earplugs are often made of waxed cotton, foam, or silicone rubber.

ear canal

The long portion of the middle ear that connects the outer ear to the inner ear. The ear canal can become damaged or blocked by wax, causing conductive hearing loss.

eardrum

A vibrating membrane that stretches across the inner end of the ear canal. The eardrum transforms vibrations into nerve impulses.

earmuffs

A protective device that blocks excessive noise and debris from entering the ear. Earmuffs consist of two ear coverings connected by a band.

earmuffs

Personal protective equipment that covers the entire outer ear. Earmuffs consist of two ear coverings connected by a band.

engineering controls

Modifications to machinery and other components to prevent or reduce noise production. Engineering controls include measures such as enclosing a machine motor to reduce the amount of noise entering the environment.

excessive noise exposure

The point at which a worker has suffered exposure to noise that surpasses safe exposure levels. Excessive noise exposure can cause hearing loss and injury.

hair cells

Sensory cells within the inner ear that support the cilia. Hair cells transform the mechanical energy of sound waves into nerve impulses.

hard hats

A lightweight, protective head covering, usually made of plastic, used to protect the head from impacts, bumps, and electric shock. Hard hats prevent head injuries, some of which can lead to hearing loss.

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 protect the hearing of employees. Hearing conservation includes wearing hearing protection.

hearing conservation program

HCP. A formal program that consists of several components intended to prevent worker hearing loss. Hearing conservation programs must include noise evaluations, hearing tests, and hearing protection.

hearing loss

A reduced ability to hear sounds. Noise exposure and heredity are two causes of hearing loss.

inner ear

The interior portion of the ear. The inner ear transforms the mechanical movement of vibration on the eardrum into nerve impulses.

middle ear

The air-filled central portion of the ear. The middle ear converts and amplifies waves in the ear canal into a vibration in the eardrum.

molded earplugs

A type of hearing protection molded to fit a specific individual’s ears. Molded earplugs, also known as pre-formed earplugs or custom-fit earplugs, are usually professionally made.

nerve impulses

Electrical signals that send and receive information to and from the brain. Nerve impulses are perceived as sounds in the brain.

NIOSH

National Institute for Occupational Safety and Health. A federal research agency tasked with researching and developing workplace health and safety recommendations. NIOSH has researched workplace hazards to determine exposure limits.

noise

Any unwanted sound. Noise can occur over a short or long period of time.

noise dosimeter

An instrument that measures total noise exposure over time. A noise dosimeter is often worn by the employee on the shoulder to measure individual noise exposure.

noise filtering earplugs

A newer variety of ear protection that reduces the sound volume in an environment without losing sound quality. Noise filtering earplugs, also called acoustic filtering earplugs or volume-reducing earplugs. are often used by musicians.

Noise Reduction Rating

NRR. A guideline that estimates the potential amount of protection a hearing protection device may provide. Noise reduction ratings can help users to select appropriate hearing protection based on the noise levels of the work they are doing.

occupational hearing loss

A reduced ability to hear sounds that is caused by exposure to loud noise in the workplace. Occupational hearing loss can negatively impact a worker's ability to do a job effectively.

Occupational Safety and Health Administration

OSHA. A government agency that sets the standards for working conditions in the United States. The Occupational Safety and Health Administration ensures that employees work in safe and healthy environments.

OSHA

The Occupational Safety and Health Administration. A government agency that sets the standards for working conditions in the United States. OSHA ensures that employees work in safe and healthy environments.

outer ear

The external portion of the ear that modifies the sound waves in the environment. The outer ear directs sound waves toward the eardrum.

Permissible Exposure Limit

PEL. Legal limits set by OSHA to protect employees from hazardous substance exposure. Permissible Exposure Limits are based on a time-weighted average for an eight-hour shift.

personal protective equipment

PPE. Any item that employees wear or use to prevent injury in the workplace. Personal protective equipment includes hard hats, earmuffs, and earplugs.

pre-formed earplugs

A type of hearing protection molded to fit a specific individual’s ears. Pre-formed earplugs, also known as molded earplugs or custom-fit earplugs, are usually professionally made.

sensorineural hearing loss

Irreversible hearing loss that is associated with the inner ear. Sensorineural hearing loss is caused by heredity, chronic noise exposure, and certain medications.

silicone rubber

A soft, pliable material that is selected for its flexibility and resilience. Silicone rubber is often used to make pre-formed earplugs.

single-use earplugs

A type of hearing protection that is disposable. Single-use earplugs, or disposable earplugs, are often made of waxed cotton, foam, or silicone rubber.

sound

The physical phenomenon that stimulates the 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 loudness. Sound-level meters can be used in place of noise dosimeters when dosimeters are unavailable or inappropriate.

time-weighted average

A measure of noise exposure that is an average of varying levels of noise experienced in a given amount of time. Time-weighted averages are used to make sure employees stay within safe noise levels.

volume-reducing earplugs

A newer variety of ear protection that reduces the sound volume in an environment without losing sound quality. Volume-reducing earplugs, also known as noise reducing earplugs or acoustic filtering earplugs, are often used by musicians.

wax

A natural secretion in the ear that protects it against dirt. Wax can build up in the ear to block sound from traveling in the ear canal.