Where visual information is needed to use a closed function, a speech or braille mode is provided, with audio through a built-in speaker or a standard headset jack the user can find without sight. Speech must be interruptible and repeatable where security permits, stop when the user acts, voice text alternatives for meaningful images and for needed pre-recorded video, never speak masked characters or private data except privately, and avoid competing sound over 3 seconds. Volume controls must be non-visual, speaker output must reach at least 65 dBA (at most 85) and reset after each user, speech must follow the displayed language, input errors must be spoken, and transaction outputs needed to verify a purchase must be voiced.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.