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.
Roman JakobsonSpeech sounds cannot be understood, delimited, classified and explained except in the light of the tasks which they perform in language.
Roman JakobsonLinguistic sounds, considered as external, physical phenomena have two aspects, the motor and the acoustic.
Roman Jakobson