At first acoustics attributed to the different sounds only a limited number of characteristic features.

Languages differ essentially in what they must convey and not in what they may convey.

Every linguistic sign is located on two axes: the axis of simultaneity and that of succession.

Speech sounds cannot be understood, delimited, classified and explained except in the light of the tasks which they perform in language.

Semantics, or the study of meaning, remained undeveloped, while phonetics made rapid progress and even came to occupy the central place in the scientific study of language.

The poetic function is the set towards the message itself, focus on the message for its own sake which by promoting the palpability of signs, deepens the fundamental dichotomy of signs and objects.

Now the identification of individual sounds by phonetic observation is an artificial way of proceeding.