The icophone is an instrument of speech synthesis conceived by Émile Leipp in 1964 and used for synthesizing the French language.[1] The two first icophones were made in the laboratory of physical mechanics of Saint-Cyr-l'École.
The principle of the icophone is the representation of the sound by a spectrograph. The spectrogram analyzes a word, a phrase, or more generally a sound, and shows the distribution of the different frequencies with their relative intensities. The first machines to synthesize words were made by displaying the form of the spectrogram on a transparent tape, which controls a series of oscillators following the presence or absence of a black mark on the tape. Leipp succeeded in decomposing the segments of a spoken sound phenomenon, and in synthesizing them from a very simplified display.[2]