Definitions. As used in this chapter, the following terms
shall have the meanings indicated:
AMBIENT NOISE LEVEL
The sound pressure level of the all-encompassing noise associated
with a given environment, being usually a composite of sounds from many sources
and/or the A-weighted sound pressure level exceeded 90% of the time/L90 based
on a one-hour period.
A-WEIGHTED SOUND PRESSURE LEVEL
The sound pressure level as measured in decibels on a sound level
meter using the A-weighting network. The level so read shall be designated
"dB(A)" or "dBA."
CONTINUOUS NOISE
A steady, fluctuating or impact noise which exists, essentially without
interruptions, for a period of one hour or more.
CYCLICALLY VARYING NOISE
A steady, fluctuating or impulsive noise which may or may not contain
a pure tone, which varies in sound pressure level such that the same level
is obtained repetitively at reasonably uniform intervals of time.
DECIBEL
A logarithmic (dimensionless) unit of measure often used in describing
the amplitude of sound. "Decibel" is denoted as "dB."
DEVICE
Any mechanism which is intended to produce or which actually produces
noise when operated or handled.
EMERGENCY VEHICLE
A motor vehicle used in response to a public calamity or to protect
persons or property from imminent danger.
EMERGENCY WORK
Work made necessary to restore property to a safe condition following
a public calamity, work to restore public utilities or work required to protect
persons or property from an imminent exposure to danger.
FLUCTUATING NOISE
The sound pressure level of a "fluctuating noise" varies more than
six dB(A)'s during the period of observation when measured with the slow meter
characteristic of a sound level meter and does not equal the previously existing
ambient noise level more than once during the period of observation.
MOTORBOAT
Any vehicle which is primarily operated on water or which does operate
on water, such as boats, barges, amphibious craft or Hovercraft, and which
is at any time propelled by mechanical power.
MOTOR VEHICLE
Any vehicle which is propelled or drawn by mechanical equipment,
such as but not limited to passenger cars, trucks, truck-trailers, semi-trailers,
campers, motorcycles, minibikes, go-carts, snowmobiles, amphibious craft on
land, dune buggies or racing vehicles.
MUFFLER
Any apparatus consisting of baffles, chambers or acoustical absorbing
materials whose primary purpose is to transmit liquids or gases while causing
a reduction in sound emission at one end.
NOISE
Any sound which is unwanted or which causes or tends to cause an
adverse psychological effect on human beings.
NOISE DISTURBANCE
Any sound which annoys, disturbs or perturbs reasonable persons with
normal sensitivities or any sound which injures or endangers the comfort,
repose, health, hearing, peace or safety of other persons.
PERSON
Any individual, association, partnership or corporation, and includes
any officer, employee, department, agency or instrumentality of the United
States, a state or any political subdivision of that state.
PLAINLY AUDIBLE NOISE
Any noise for which the information content of that noise is unambiguously
communicated to the listener, such as but not limited to understandable spoken
speech or comprehensible musical rhythms.
POWERED MODEL VEHICLES
Any power vehicles, either airborne, waterborne or landborne, which
are designed not to carry persons or property, such as but not limited to
model airplanes, boats, cars and rockets, and which can be propelled by mechanical
means.
PROPERTY BOUNDARY
An imaginary line at the ground surface which separates the real
property owned by one person from that owned by another person, and its vertical
extension.
PURE TONE
Any noise which can be distinctly heard as a single pitch or a set
of single pitches. For the purposes of measurement, a pure tone shall exist
if the one-third octave band sound pressure level in the band with the tone
exceeds the arithmetic average of the sound pressure levels of the two contiguous
one-third octave bands by five dB's for frequencies of 500 hertz and above,
by eight dB's for frequencies between 160 and 400 hertz and by 15 dB's for
frequencies less than or equal to 125 hertz.
REPETITIVE IMPULSIVE NOISE
Any noise which is composed of impulsive noises that are repeated
at sufficiently slow rates such that a sound level meter set at fast meter
characteristic will show changes in sound pressure level greater than two
dB(A)'s.
SOUND
A temporal and spatial oscillation in pressure or other physical
quantity in a medium with internal forces that causes compression and rarefaction
of that medium and which propagates at finite speed to distant points.
SOUND LEVEL METER
An instrument, which includes a microphone, amplifier, RMS detector,
integrator or time averager, output meter and weighting networks used to measure
sound pressure levels.
SOUND PRESSURE
The instantaneous difference between the actual pressure and the
average or barometric pressure at a given point in space.
STATIONARY EMERGENCY SIGNALING DEVICE
Any device, excluding those attached to motor vehicles, used to alert
persons engaged in emergency operations. These include but are not limited
to fire fighters, first aid squad members and law enforcement officers, whether
paid or volunteer.
STATIONARY NOISE SOURCE
Any device, fixed or movable, which is located or used on geographically
defined real property other than a public right-of-way.
STEADY NOISE
A sound pressure level which remains essentially constant during
the period of observation, i.e., the fluctuations are too small to meet the
criterion for fluctuating noise.
WEEKDAY
Any Monday, Tuesday, Wednesday, Thursday or Friday which is not a
legal holiday.