Module C - Slide 31
And here are the requirements related to the walk indication:
Quiet, not broadcast across intersection
Audible at crosswalk departure point
Vibrotactile indication (in addition to audible)
Where APS on corner can be separated
Rapid tick
Where two APS are located on same pole or closer than 10 feet to each other
Speech walk message with a tactile arrow and a pushbutton Information message