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

Linguistic sounds, considered as external, physical phenomena have two aspects, the motor and the acoustic.

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

Acoustic phonetics, which is developing and increasing in richness very rapidly, already enables us to solve many of the mysteries of sound, mysteries which motor phonetics could not even begin to solve.

When I speak it is in order to be heard.

What's next? Shall we appoint elephants to teach zoology?

It is once again the vexing problem of identity within variety; without a solution to this disturbing problem there can be no system, no classification.