Audio accessibility is the set of features and tracks that make audio content usable by everyone, much of it legally required. It spans audio description (a narrated track describing visual action for blind and low-vision viewers), clean-dialogue or dialogue-enhancement tracks that let viewers raise speech over music and effects, spoken-subtitle and signed-audio options, and correct labelling so assistive technology and player menus can find them. In streaming these arrive as tagged audio renditions with role and accessibility metadata; in next-generation codecs like AC-4 and MPEG-H some are rendered from objects on the device. Regulations — the CVAA in the US, the European Accessibility Act, and others — mandate much of this, so accessibility is both an ethical baseline and a compliance requirement.
