Vocate Luria on oral v written speech

Careful analysis by Vygotskii ( 1956) and El'konin ( 1954) indicated that written speech represents an entirely new psychological phenomenon, different from oral speech.
Oral speech forms during immediately practical intercourse and its component elements long remain insufficiently conscious, unseparated by the child from general speech activity ( Morozova, 1948; Karpova, 1955). Written speech follows exactly the opposite course. It is always the product of special training, which presupposes the separation of individual words from the flow of living speech and individual sounds from the living word. It also involves abstraction from individual phonations of sounds and the conversion of sounds into stable phonemes. This process of analysis, described in the Soviet literature by Luria ( 1950), Nazarova ( 1952), and others is a necessary technical premise for the act of writing, which from the very beginning requires conscious effort.
Oral speech always originates in close connection with immediate experience, as, for example, in sympractical and situational activity. It relies on intonation and gesture and usually becomes intelligible only if the general setting of the conversation is considered. It permits extensive abbreviation. For a prolonged period it continues to bear traces of the period when the subject was contained in speech and the predicate in a gesture, a tone, or in the immediate situation. Written speech . . . is deprived of this sympractical context, and therefore it must be more detailed, contextual, or, to use Buhler's term, synsemantic. Written speech like a work of art, to paraphrase Leonardo da Vinci, should contain within itself all means of expressiveness and in no way depend on the concrete environment. ( Luria, 1969c, pp. 141142)