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.
Normal human hearing ranges from 20 hertz to 20,000 hertz. Low-frequency sounds, below 20 hertz, are referred to as âinfrasoundâ and travel farther than high-frequency sounds. Frequencies above the range of human hearing (20,000 hertz) are referred to as âultrasonic.â.lthough the upper end of human hearing is about 20,000 hertz, deer can hear frequencies to at least 30,000 hertz. But, these high-frequency sounds must be louder because high-frequency sounds donât travel as far as low-frequency sounds. Hearing and Vocal Communication.