SAN FRANCISCO (Reuters) – Karrie Karahalios can show a child with Asperger’s Syndrome when he’s lost in a conversational riff or a taciturn spouse when he doesn’t speak very much.

Their voice appears on a computer terminal as vibrant colors — red, yellow, blue, green — the image growing in size if the voice gets louder, overlapping another color as it interrupts or abruptly narrowing with silence.

They are talking in color….