Audio quality in audio description: Getting the priorities right (June 2015)

Audio description (AD) is an accessibility service consistent on describing the visual parts of a film or show through spoken comments inserted where there is no dialogue. This research restricts to AD of pre-recorded content to be TV broadcasted. Different recommendations have been issued by governments, broadcasters and blind associations aimed at regulating AD, and establishing a common quality standard, but they leave the issue of AD loudness largely unregulated. Regulations like EBU R128 aim at regulating loudness in behalf of the TV viewer, but no similar legislation exists for Audio description. This article deals with the concept of sound quality in audio description and suggests methods to objectively measure and control volume levels in TV broadcasted audio description. To date, there is no objective standard on volume levels suggested in any audio description guidance document for the audio description track inserted into a programme. We propose adopting the criterion established by EBU R128 of normalization at -23 LUFS (Loudness Unit Full Scale) for the track inserted as departure point for the sound mixing process. This would provide an objective base to work with and check whether the narrative comments inserted as the audio description track into a film or programme should be at the same volume level as the background original soundtrack, above the original soundtrack or below, and with how many decibels of difference between the two.