All terminology used in this chapter shall be in conformance
with the applicable publications of the most current edition of the
American National Standards Institute (ANSI) or its successor body.
The following words and terms, as used herein, shall have the following
meanings:
A-WEIGHTED SOUND PRESSURE LEVEL (SPL)
The logarithmic sum of the decibel levels of the full frequency
range between 20 Hz and 20,000 Hz weighted to correlate to the loudness
of sounds as perceived by the human ear using the A-weighted network.
BACKGROUND SOUND LEVEL
The measured sound level in the area, exclusive of spontaneous,
extraneous sounds, and the sound contribution of the specific source
in question.
DECIBEL (dBA)
A unit for measuring the sound-pressure level, equal to 20
times the logarithm to the base 10 of the ratio of the pressure of
the sound measured to the reference pressure, which is 20 micropascals
or 0.0002 microbar.
DIRECTOR
The Director of the Building and Planning Department of the
Township of Lower Merion.
EQUIVALENT CONTINUOUS SOUND PRESSURE LEVEL (LEQ)
The constant sound level which contains the same amount of
sound energy over a given time period as the fluctuating sound. It
is considered to be the average sound level within each measurement
period. The LEQ shall be measured on the A-weighted scale, and the
time interval shall be 10 minutes.
MEASUREMENT INSTRUMENT
A Type I or Type II sound level meter as specified by the
most current ANSI standard using the A-weighting network as specified
in the most current edition of the ANSI standard or its successor.
PERSON
Any individual, firm, corporation, association or partnership.
PROPERTY LINE
The boundary between adjoining lots, dwelling units, and
condominium units owned, rented or leased by different persons, and
also, for any two or more buildings on the same lot, the line drawn
midway between any two said buildings.
RESIDENTIAL DISTRICT(S)
Land within an LDR1; LDR2; LDR3; LDR4; MDR1; MDR2; or MDR3 Residence District as provided in Chapter
155 of the Township Code.
[Amended 2-26-2020 by Ord. No. 4184]