[...] a speech-sound [...] must be [...] associated with some element or group of elements of experience, say a visual image or a class of visual images or a feeling of relation, before it has even rudimentary linguistic significance.
- Sapir (1921), a pag.11

[...] 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- that in which the sound is replaced by the visual image of the articulations that correspond to the sound.
- Sapir (1921), a pag.19

The letter of the telegraph code is thus a symbol of a symbol of a symbol. It does not, [...] follow that the skilled operator [...] needs to transpose the individual sequence of ticks into a visual image of the word before he experiences its normal auditory image.
- Sapir (1921), a pag.20