My research is concerned with the coherence of the notion of language delay, drawn from Natural Aural deaf education. Empirical evidence strongly indicates that children who have not acquired the underlying structures of the functional grammar (Radford, 1990) of their target language prior to four years of age do not subsequently develop a functional grammar; a finding that renders the notion of language delay, within this context, empirically incoherent. Instead, the coherence of language delay is found to reside within Natural Auralism as a discursive practice. Contradictions between the empirical data and the discursive practice surrounding language delay within Natural Auralism are investigated from the theoretical perspective of a version of Chaos Theory, which I develop as model2 theory. Model2 theory is then used to explain why children who have not achieved a functional grammar prior to four years of age suffer an enduring and protracted language delay within a broader model2 description of the process of language acquisition, which is also critical of some aspects of Chomsky's work on grammar, in particular Logical Form.