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.
dBa
The abbreviation designating the unit of sound level as measured
by a sound level meter using the A-weighting.
DECIBEL
The practical unit of measurement for sound pressure level;
the number of decibels of a measured sound is equal to 20 times the
logarithm to the base 10 of the ratio of the sound pressure of the
measured sound to the sound pressure of a (20 micropascals); abbreviated
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 an unexpected occurrence
or situation resulting from natural or unnatural causes which endangers
or has the potential to endanger the health, safety or resources of
citizens or a municipality, and, as such, necessitates prompt action
and response on the part of the emergency services personnel.
EMERGENCY WORK
Work 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 a boat, barge, amphibious craft, watercraft,
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,
semitrailers, campers, motorcycles, minibikes, go-carts, snowmobiles,
amphibious craft on land, dune buggies, racing vehicles or any motorized
vehicle having two or more axles.
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, company, corporation,
society, officer, employee, department, agency, other entity 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 powered vehicles, either airborne, waterborne or landborne,
which are designated 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, and its vertical
extension, which separates the real property owned by one person from
that owned by another person.
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 1/3 octave band sound pressure level in the
band with the tone exceeds the arithmetic average of the sound pressure
levels of the two contiguous 1/3 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 a single pressure peak or
a single burst (multiple pressure peaks) having a duration of less
than one second that is repeated at sufficiently slow rates such that
a sound level meter set at fast meter characteristic will slow 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 a 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 of barometric pressure at a given point in space,
the level of which can be measured in dB units with a sound level
meter which has a uniform (“flat”) response over the band
of frequencies measured.
STATIONARY EMERGENCY SIGNALING DEVICES
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.