MLBB4D Stereo audio transmissions, using the NICAM digital stereo sound format began on BBC1 in late 1987, to coincide with the sale of the first consumer NICAM-enabled equipment, a year after BBC2, and were gradually phased in across BBC TV output, although it took until 31 August 1991 for the service to begin officially on both channels.|{3|4|5|6|7|8|9|10|Three|Four|Five|Six|Seven|Eight|Nine|Ten} Ways Twitter Destroyed My Slot Hub Without Me Noticing