This Recommendation specifies an advanced sound system with and without accompanying picture@ beyond systems specified in Recommendation ITU-R BS.775. An advanced sound system uses audio data in combination with an appropriate set of metadata to specify a sound scene to be delivered/broadcasted. The specifications include requirements for signalling the properties of advanced sound content and speaker layout to be used in content production for advanced sound systems. The advanced sound system can apply to the sound component of television and expanded large screen digital imagery (LSDI) programmes@ as well as for sound only programmes.