Dead air is a phenomenon whereby a broadcast which normally carries audio or video unintentionally becomes silent or blank. The term is most often used in cases where programme material comes to an unexpected halt, either through operator error or for technical reasons, although it is also used in cases where a broadcaster has 'dried up'. It is the duty of all concerned to rectify the problem as quickly as possible; in many parts of the world dead air is considered to be one of the worst crimes a broadcaster can commit.
A widely known example of dead air was a Chris Evans radio transmission for the British Virgin Radio station. As a promotional stunt, Chris never arrived for work, and his show went to air carrying nothing for about 25 minutes. Almost as infamous was BBC Radio Four's failure to broadcast Big Ben's midnight chimes on New Year's Day 2003; after announcing the chimes, a technical error caused the station to fall silent for a minute.
Under British broadcasting laws, any radio station which transmits dead air for more than 10 minutes without rectifying the situation, broadcasting an announcement or warning its listeners can be penalised or fined up to £25,000 per minute. The regulator for this used to be the Radio Authority, which has since become part of OFCOM, a unit of the British government.
Dead air can also apply to television broadcasting, generally when a television channel has an interruption to its output, resulting in a blank screen or in the case of digital television, a frozen image, until output is restored or an apology message is broadcast.
See also