[Code of Federal Regulations] [Title 43, Volume 1] [Revised as of October 1, 2002] From the U.S. Government Printing Office via GPO Access [CITE: 43CFR421.11] [Page 589] TITLE 43--PUBLIC LANDS: INTERIOR CHAPTER I--BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR PART 421--RULES OF CONDUCT AT HOOVER DAM--Table of Contents Sec. 421.11 Audio devices. The operation or use of a public address system is prohibited, except when specifically authorized by the Bureau of Reclamation.