Certain wireless microphones can create interference over spectrum bands used for critical public safety communications and wireless broadband services. To preserve the integrity of those communications, the FCC prohibits the use of wireless microphones and similar devices that operate between 698 and 806 MHz (known as the “700 MHz Band”). Similar devices, such as wireless intercoms, in-ear monitors, audio instrument links and cueing equipment, are also prohibited. Wireless device operators -- including theaters, churches, schools, conference centers, and theme parks -- were required to retune or replace their equipment no later than June 12, 2010. Wireless microphone operations outside of the 700 MHz Band were not affected by this prohibition. Learn more about prohibitions and background at the FCC Encyclopedia .