SMPTE EG 23:2005

Scope:

(1.1) This guideline specifies the handling of volume range issues when transferring two-channel stereo audio from 35-mm or 16-mm magnetic film, or other audio tape formats utilizing time-code based methods of synchronization, to any video recording media. (1.2) Among the volume range issues are both objective and subjective ones, including: — most end users will usually adjust loudness so that dialog is reproduced at a normalized level (despite how loud or soft other parts of the program may be) for best intelligibility; — dubbing stages and monitor theaters are often operated at higher reference sound pressure levels than the end video consumer will use; — commercials may well be intercut with program material, creating the potential for abrupt level changes among video sources; — many of the video formats have reduced audio dynamic range capability when compared to magnetic audio-only masters; — video transmission involves at least a 75-ms preemphasis network in the transmitter, and often much more nonstandardized audio signal processing, which has an impact on the volume range relationships within the program material. (1.3) The guideline also specifies certain labeling requirements for audio masters.