Noise Report [As Published] · 132007.2398

ASL Care

Proposed RSL Retirement Village, Cooroy — Road and Rail Noise Assessment

 

APPENDIX B: GLOSSARY OF ACOUSTIC TERMINOLOGY

A-Weighting

dB (decibe!)

dB(A)

Facade Noise Level

Free Field

Hertz (Hz)

Laeg

Equivatent Continuous
Sound Level!

Lyso,t

Lato,

Laso, T

Lwa

A response provided by an electronic circuit which modifies
sound in such a way that the resulting level is similar to
that perceived by the human ear.

This is the scale on which sound pressure level is
expressed. It is defined as 20 times the logarithm of the
ratio between the root-mean-square pressure of the sound
field and the reference pressure (0.00002N/m’).

This is a measure of the overall noise level of sound
across the audible spectrum with frequency weighting (i.e.
‘A’ weighting) to compensate for the varying sensitivity of
the human ear to sound at different frequencies.

Refers to a sound pressure level determined at a point
close to an acoustically reflective surface (in addition to the
ground). Typically a distance of 1 metre is used.

Refers to a sound pressure level determined at a point
away from reflective surfaces other than the ground with
no significant contribution due to sound from other
reflective surfaces; generally as measured outside and
away from buildings.

A measure of the frequency of sound. {!t measures the
number of pressure peaks per second passing a point
when a pure tone is present.

This is the equivalent steady sound level in dB(A)
containing the same acoustic energy as the actual
fluctuating sound level over the given period. For a steady
sound with small fluctuations, its value is close to the
average sound pressure level.

This is the dB(A) level exceeded 90% of the time, T.

This is the dB(A) level exceeded 10% of the time, T.

This is the dB(A) level exceeded 50% of the time, T.

The A-weighted sound power level in dB.

 

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