Sheriff Jack W. Brandes. To serve and protect the citizens of Austin County and the great State of Texas and to preserve and protect the. Constitution of the United States of America, especially the Second Amendment, the Right to Bear Arms..
Integrating Sound Level Meter. In atmospheric sounding and noise pollution, ambient noise level (sometimes called background noise level, reference sound level, or room noise level) is the background sound pressure level at a given location, normally specified as a reference level to study a new intrusive sound source.
The defined sound level is therefore not the perceived loudness of a sound. We get a rough approximation to human auditory perception by the use of an A-weighted filter, which approximates the sound signal in the different frequency areas according to the sensitivity of the hearing mechanism, but only at low levels.