An electronic filter that allows only the frequencies lower than a given point to be heard, eliminating all frequencies above a given point. The exact filter point is equipment and/or setting specific, but is typically 6 - 12 KHz which helps eliminate sibilance and hissing.

Source: [http://www.allchurchsound.com/ACS/glossary/index.html Church Audio & Acoustics Glossary] [[Category: Acoustics]]