Monday, February 24th @ 3:00 PM, Kent 107

Investigating phonetic variation over time in the U.S. Supreme Court

Phonetic research over the past two decades has shown that individual speakers vary their phonetic realizations of words, phonemes, and subphonemic features. What we have found is that speakers show remarkable stability over time, while a small minority exhibit time-dependent variation—what we term change. Prior research has shown that individual-level phonetic change can occur at scales ranging from minutes (as induced in laboratory experiments (Nielsen 2007, Babel 2009, Yu et al. 2013) to years (as observed in speech corpora, e.g., Sankoff 2004, Harrington 2006). Significantly, this research suggests that individual change in both the short and long term may ultimately be a crucial component of sound change in a population.

The SCOTUS speech corpus project is concerned with this kind of individual variation and change. How do different phonetic variables vary over time? How do different speakers vary their pronunciations over time? That is, what time dependence, if any, do different phonetic variables show within individual speakers, and how might individuals’ variation patterns converge with one another?  These are the questions which I seek to address. My research will yield three types of contributions: an extensive speech corpus for studying the link between social interaction and language change; a study of change within individuals and within a group of speakers over time; and an exploration of the relationship between different individuals’ patterns of variation (which may be time-dependent), as mediated by linguistic, social, and environmental factors.  In this talk, I introduce the SCOTUS speech corpus, a digital audio archive of U.S. Supreme Court oral argument recordings transcribed to phoneme level via forced alignment.  I then describe an ongoing longitudinal study of phonetic variation and convergence using the corpus, which will analyze the speech of the justices of the Supreme Court over a period of 7 years. Using data from one term year as a case study, I present preliminary findings on one phonetic variable, vowel formants, and situate the current project within past research on phonetic variation and change over time.