- the representation in graphic or pictorial form of characteristics of speech, as by means of sound spectrograms.
- the system of handwritten phonetic symbols invented by Melville Bell in 1867 to provide a visually comprehensible rendition of speech sounds.
- a system of phonetic notation invented by Alexander Melville Bell (1819–1905) that utilized symbols based on the schematic representation of the articulations used for each speech sound
