Broadcast studios also use many of the same principles such as sound isolation, with adaptations suited to the live on-air nature of their use. Such equipment would commonly include a telephone hybrid for putting telephone calls on the air, a POTS codec for receiving remote broadcasts, a dead air alarm for detecting unexpected silence, and a broadcast delay for dropping anything from coughs to profanity. In the U.S., stations licensed by the Federal Communications Commission (FCC) also must have an Emergency Alert System decoder (typically in the studio), and in the case of full-power stations, an encoder that can interrupt programming on all channels which a station transmits to broadcast urgent warnings.