The vocal nature of human language is certainly no peripheral aspect of it, but a basic feature, without which linguistic organization might be fundamentally different from what we know it to be.
- Martinet (1962), a pag.26

Yet, there is one important argument in favour of including vocal nature in our definition, namely that vocal quality is directly responsible for the linearity of the speech and the consequent linearity of the script. It is clear that if signs were visual and presented on a surface, there would be no need for language to be manifested by a succession of items […].
- Martinet (1962), a pag.25