[...] interjections are merely conventional fixations of the natural sounds.
- Sapir (1921), a pag.5

Such words as 'whippoorwill,' 'to mew,' 'to caw' are in no sense natural sounds that man has instinctively or automatically reproduced.
- Sapir (1921), a pag.7

[...] a number of words which we do not now feel to have a sound-imitative value can be shown to have once had a phonetic form that strongly suggests their origin as imitations of natural sounds.
- Sapir (1921), a pag.7

However much we may be disposed [...] to assign a fundamental importance in the languages of primitive peoples to the imitation of natural sounds, [...] these languages show no particular preference for imitative words.
- Sapir (1921), a pag.8