Although permissible, you are not required to have a video or audio monitoring system.     
     Source Note:        The provisions of this §746.3705 adopted to be effective September 1, 2003, 28 TexReg 1402; amended to be effective December 1, 2010, 35 TexReg 10238; transferred effective March 9, 2018, as published in the Texas Register February 16, 2018, 43 TexReg 909