[...] there are two logically possible elementary ways in which linguistic forms can differ from each other: quantitatively and qualitatively. [...] Quantitative differences [...] pertain to the duration of the production and perception of a sound property. Thus, the two sound form "ab" and "abb" differ neither in their sound properties nor in the temporal relations of their sound properties: their distinctness stems from the fact that "bb" of "abb" has a duration that extends over a larger number of time units than the duration of the "b" of "ab", whether due to prolonged articulation or to repeates articulation.
- Moravcsik (2004), Pag. 310