Abstract
Almost universally, diachronic sound patterns of languages reveal evidence of both regular and irregular sound changes, yet an exception may be the languages of Australia. Here we discuss a long-observed and striking characteristic of diachronic sound patterns in Australian languages, namely the scarcity of evidence they present for regular sound change. Since the regularity assumption is fundamental to the comparative method, Australian languages pose an interesting challenge for linguistic theory. We examine the situation from two different angles. We identify potential explanations for the lack of evidence of regular sound change, reasoning from the nature of synchronic Australian phonologies; and we emphasise how this unusual characteristic of Australian languages may demand new methods of evaluating evidence for diachronic relatedness and new thinking about the nature of intergenerational transmission. We refer the reader also to Bowern (this volume) for additional viewpoints from which the Australian conundrum can be approached.