Theoretical achievements of phonetics in the 21st century: Phonetics of voice quality

Twenty years after the publication of a special issue in this journal on non-modal phonation (JPhon 2001: 49(4)), the phonetic study of voice quality has shown impressive progress. Here I focus on what we have learnt over these years about the linguistic sources of voice quality modulation. I stress how voice quality has a role to play in all of speech: among its many functions, the voice is involved in the articulation of all sounds, and voice quality is worth investigating as much for “modal” consonants and vowels as for contrastive phonation type. The voice also encodes structure at many prosodic levels: sub-lexical, lexical, and post-lexical. I further highlight some of the important technological developments and refinement of various voice quality models that have led to progress in the phonetic study of voice quality. Reviewing all of the above, one can only conclude that human voice has a central role to play in the phonetician’s pursuit towards understanding spoken language.