Microvariation, variation, and the features of universal grammar

Accounting for the tremendous diversity of acoustic realizations of what linguists label as the ‘same’ sounds (featurally and/or implicitly through use of IPA symbols) cross-linguistically is a challenging task. Since a certain amount of this diversity is directly reflected in the input data presented to acquirers, and since determining its source is a key component of phonological learning, it is crucial for any account of early phonological acquisition that we develop an understanding of the sources of this diversity. This paper presents an explicit account of types and sources of such diversity, which we will term ‘microvariation,’ and makes a critical distinction between microvariation – a product of various extra-grammatical mechanisms and properties – and phonology. Differences in acoustic realizations due to differences in phonological feature representations, which we will call ‘variation’, should, we maintain, be treated as entirely separate phenomena (although they clearly produce cross-linguistic diversity, as well). A close examination reveals that variation (feature-based distinctions) can be obscured by microvariation and that microvariation can be mistakenly taken as representing variation. Teasing these apart provides us with a clearer understanding of the nature of the grammar and its acquisition, as well as of its interaction with other systems.