Noise - glossary
Acoustic trauma
The damage to the hearing mechanism caused by a sudden burst of high-energy noise. Acoustic trauma is usually considered to be caused by a single impulsive event with a very high peak sound level
Acoustics
The science of sound, including the generation, transmission and effects of sound waves, both audible and inaudible
Amplitude
The strength of a sound signal, as detected by the ear or as measured by a sound level meter
Attenuation
The reduction of the force, effect, or value of anything
Average noise level
A notional steady level that contains the same amount of noise as the actual fluctuating noise level during a specified period of time
Audibility
Capability of being heard
Audiometric evaluation
A non-invasive hearing test that measures a persons ability to hear different sounds, pitches or frequencies
Audiometry
Testing of an individuals ability to hear various sound frequencies
Auditory threshold
The slightest perceptible sound or sound intensity required to be heard
Cardiovascular
Relating to or involving the heart and blood vessels
Case management
A collaborative process which assesses, plans, implements, co-ordinates, monitors and evaluates the options and services required to meet an individuals health, social care, educational and employment needs
Convention
An agreement between states covering a particular issue
Cumulative
The total or overall sound level for the whole of a noise measurement interval from the start time to the stop time, including everything that occurs during the measurement run
Daily exposure
The noise a worker is exposed to during a working day, taking account of the magnitude and duration of the noise
Decibel
The unit of sound pressure, usually abbreviated to dB
Durable
Able to withstand wear, pressure or damage
Ear-muffs
Personal hearing protectors that are worn over the whole of the outer ear to minimise hearing loss in high noise levels
Ear-plugs
Personal hearing protectors that are worn inside the ear canal of the outer ear to minimise hearing loss in high noise levels
Exchange rate
The exchange rate is the amount by which the permitted sound level may increase if the exposure time is halved
Exposure action value
A daily amount of noise exposure above which employers are required to take action to control it
Exposure limit
The maximum amount of noise a worker may be exposed to on any single day
Frequency
The number of times a second that a sine wave of sound, or a vibrating object, repeats itself. The more repeats per second, the higher the frequency is said to be. The unit of frequency is Hertz
Hearing threshold level
The amount, in decibels, by which an individuals threshold of audibility differs from that of a normal standard audiometric threshold
Humidity
The amount of water vapour (moisture) in the atmosphere
Impulsive noise
A single or multiple sound pressure peak with a rise time or total duration less than 200 milliseconds
Induction loop
A sound system in which a loop of wire around an area in a building produces an electromagnetic signal received directly by hearing aids used by individuals who are partially deaf
Intermittent
Occurring at irregular intervals
Legislation
Law enacted by a legislative body at the national, state or local level
Occupational physician
A doctor with specialist training and qualifications in occupational medicine
Permanent threshold shift
A permanent shift in the auditory threshold, an irreversible condition of the inner ear caused by damage to the individual hair cells in the cochlea
Presbycusis
The reduction in human hearing acuity attributed simply to the normal ageing process
Proactive
Creating or controlling a situation rather than just responding to it after it has happened
PVC
A synthetic thermoplastic material made by polymerising vinyl chloride
Rehabilitation
The process whereby an individual uses the services of various professionals to restore any functionality they've lost due to illness or injury
Temporary threshold shift
A temporary impairment of hearing acuity as indicated by a change in the threshold of audibility
Tinnitus
A sense of ringing in the ears or noise in the head