Audio description is an additional narrated track that describes the on-screen visual action — who entered, what they're doing, a key gesture — in the gaps between dialogue, so blind and low-vision viewers can follow the story. It is delivered as its own audio rendition, either pre-mixed with the program or, in newer object-based systems, as a separate object the receiver mixes in. Accessibility regulations in the US (FCC/CVAA), the EU (EAA), Canada, and the UK mandate it for broadcasters and increasingly for streaming, with minimum hours and discoverability requirements. Producing it well is a craft: timing, level, and word economy decide whether the description helps or talks over the moment.
The book · Volume 4 of 7
Audio for Video: A Complete Guide to Sound in Video Products: From PCM and Codecs to Loudness, Accessibility, and Real-Time Voice Processing
Audio description is often legally required, yet many platforms cannot deliver it as a proper selectable track. Volume 4 covers audio description in detail within accessibility: description tracks, dialogue enhancement, captions and subtitles, multi-language audio and loudness for alternate mixes. Written by Nikolay Sapunov, CEO at Fora Soft.
Need to deliver audio description tracks on your platform?
Tell us your content and players, and we will plan how audio description is produced, packaged and selected in each player. 250+ video products shipped since 2005.
