Language is primarily an auditory system of symbols. In so far as it is articulated it is also a motor system, but the motor aspect of speech is clearly secondary to the auditory.
- Sapir (1921), a pag.17

[...] let us suppose that one not only hears the articulated sounds but sees the articulations themselves as they are being executed by the speaker. [...] if one can only gain a sufficiently high degree of adroitness in perceiving these movements of the speech organs, the way is opened for a new type of speech symbolism [...] in which the sound is replaced by [...] the articulations that correspond to the sound.
- Sapir (1921), a pag.19

[...] we are already possessed of the auditory-motor system of which it is at best but an imperfect translation, not all the articulations being visible to the eye. [...] it is well known what excellent use deaf-mutes can make of 'reading from the lips' as a subsidiary method of apprehending speech.
- Sapir (1921), a pag.19

There are [...] an indefinitely large number of articulated sounds available for the mechanics of speech; any given language makes use of an explicit, rigidly economical selection of these rich resources [...]
- Sapir (1921), a pag.46

The voiceless sounds are articulated noises that break up the stream of voice with fleeting moments of silence.
- Sapir (1921), a pag.49