visible speech

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A system of phonetic notation used as an aid for teaching speech to hearing-impaired people and consisting of diagrams of the organs of speech in the various positions required to articulate sounds.

from the GNU version of the Collaborative International Dictionary of English.

• (Phon.) A system of characters invented by Prof. Alexander Melville Bell to represent all sounds that may be uttered by the speech organs, and intended to be suggestive of the position of the organs of speech in uttering them.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun spectrogram of speech; speech displayed spectrographically
• noun a phonetic alphabet invented by Melville Bell in the 19th century