Speech compression CODIMEX system

A relatively simple installation is sufficient to obtain a four-to-one reduction of the frequency bandwidth occupied by a telephonic signal. The speech is decomposed into its three principal formants which constitute the basic information carrying elements. Each of these formants is compressed both in amplitude and in frequency following a definite mathematical law, and in accordance with a specified formula for transforming the frequency spectrum. The speech obtained is highly intelligible and the spectrum of the reconstituted signal is a satisfactory reproduction of that of the initial telephonic signal. The installation enables additional telephonic communications to be transmitted in the existing channels. CODIMEX means: COmpression, DIvision, Multiplication, EXpansion.