Specific Definitions.
AMBIENT SOUND PRESSURE LEVEL
The all-encompassing background sound pressure levels associated
with a given environment at a specified time, without the sound contribution
of the specific source in question. Ambient noise is usually a composite
of sounds from near and far sources, none of which is particularly
dominant.
ANSI
American National Standards Institute or its successors.
BACKGROUND NOISE
The total noise from all sources other than a particular
sound that is of interest (i.e., other than the sound being measured).
CONTINUOUS SOUND
Any sound which is in a steady, fluctuating or intermittent
state of prolonged duration.
DECIBEL (dB)
A unit of level which denotes the ratio between two quantities
that are proportional to power; the number of decibels is 10 times
the common logarithm of this ratio. One decibel is 1/10 of a bel.
EXCESSIVE NOISE
Excessive noise is sound that: (1) is injurious or unreasonably
interferes with the comfortable enjoyment of life and property. Measured
noise levels in excess of limits established in these regulations
or those specified in valid permits are declared to be excessive noise;
(2) is annoying to a person of ordinary auditory sensibilities.
IMPULSIVE SOUND
Any sound of short duration (less than one second), with
an abrupt onset and rapid decay (including metal-to-metal impacts
or exploding impacts) separated in time by at least one second.
NIGHT TIME
10:00 p.m. to 7:00 a.m., prevailing time, conversely, Day
Time- 7:00 a.m. to 10:00 p.m., prevailing time.
NOISE
Any sound which annoys or disturbs humans of normal auditory
sensitivity or which causes or tends to cause an adverse psychological
or physiological effect on humans of normal auditory sensitivity,
excluding all aspects of noise regulated by the Federal Occupational
Safety and Health Act.
NOISE LEVEL
Same as sound level but usually used to describe unwanted
sound.
NOISE POLLUTION
Noise of such loudness and character from a single source
or from multiple sources, which is or may be predicted with reasonable
certainty to be, injurious to health or which unreasonably interferes
with the enjoyment of property or with any lawful business or activity.
Noise/sound pressure levels exceeding those permitted in any district
shall constitute noise pollution.
NORMAL AGRICULTURAL OPERATION
The customary and generally accepted activities, practices
and procedures that farmers adopt, use or engage in year after year
in the production and preparation for market of poultry, livestock
and their products, and in the production and harvesting of agricultural,
agronomic, horticultural, silvicultural and aquacultural crops and
commodities.
PERIOD OF OBSERVATION
The time interval during which acoustical data are obtained.
The period of observation is determined by the characteristics of
the noise being measured and the instrumentation being used. The period
of observation must be at least as long as the response time of the
instrumentation. The greater the variance in individual sound level,
the longer must be the observation time for a given expected accuracy
of measurement.
PERSON
Includes an individual, firm, association, organization,
partnership, trust, company, corporation or any other similar entity.
PURE TONE
A sound that can be distinctly heard as a single pitch or
a set of single pitches. For the purposes of this Part, 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 15 dB for bands with
center frequencies less than 160 Hz, by 8 dB for bands with center
frequencies of 160 Hz to 400 Hz, and by five dB for bands with center
frequencies greater than 400 Hz.
SOUND LEVEL (UNWEIGHTED SOUND PRESSURE LEVEL)
20 times the common logarithm of the ratio of a given sound
pressure (obtained with a standardized frequency weighting, with standard
exponentially weighted time averaging) to the reference sound pressure
of 20 micropascals. Time and frequency weightings employed should
be specified; if not specified, fast time- and A- frequency-weightings
are understood. Unit symbol: dB.
SOUND LEVEL METER
Instrument or combination of instruments used for the measurement
of sound level, with a standard frequency-weighting and standard exponentially
weighted time-averaging, which meets or exceeds the requirements for
an ANSI Type S1A or Type S2A Sound Level Meter.
SOUND PRESSURE LEVEL
In air, 20 times the common logarithm of the ratio of the
given sound pressure to the reference sound pressure of 20 micropascals.
Unit symbol: dB.
TOWNSHIP
East Rockhill Township, Bucks County, Pennsylvania, its Board
of Supervisors, Township Manager, and all employees and appointees
of the Township.
VEHICLE
Any device or combination of devices, used for or capable
of being used for transporting persons or property. Vehicles include,
but are not limited to, the following: automobiles, trucks, buses,
motorcycles, motorized bicycles, snowmobiles, scooters, all-terrain
vehicles, go-carts, farm machinery, industrial machinery, highway
graders, tractor-trailers, and semi-trailers.