Advancements of phonetics in the 21st century: Theoretical and empirical issues in the phonetics of sound change

It has long been understood that speakers produce and listeners perceive non-random, systematic phonetic variants that serve as the raw material for sound change. This understanding underlies much of the current research on the phonetic underpinnings of change, which includes study of (i) general phonetic principles underlying variation, (ii) specific phonetic ‘preconditions’ and biases arguably linked to specific patterns of phonological instability and change, and (iii) the production and perception of variation by speaker-listeners in situations of actual ongoing change and by interacting agents in computational simulations of change. This paper shows how findings from these three broad areas of study have led to 21st century theoretical and empirical advancements in our understanding of phonetic change. Big-picture questions about the nature of change are approached through consideration of a series of smaller, more tractable questions (e.g., about the nature of, and relation between, innovative speaking and innovative listening for both stable patterns of variation and ongoing change). The paper’s goals are to show, for these questions, their theoretical grounding, empirical challenges, preliminary answers and, in turn, the new theoretical directions emerging from those answers.