Jessamyn Schertz (faculty) and Sarah Khan (MA) have a paper out in the Journal of Phonetics, 81: "Acoustic cues in production and perception of the four-way stop laryngeal contrast in Hindi and Urdu."
This work examines cue weighting in production and perception of the four-way laryngeal contrast in Hindi and Urdu. Previous work has consistently identified several cues, including prevoicing (duration), aspiration (duration), voice quality, and f0, that are relevant to the contrast, although the phonetic specification of the contrast, and particularly the status of the so-called “voiced aspirates,” remains unclear. In this work, we confirm the importance of prevoicing and aspiration to the contrast overall, but argue that voice quality (murmur or breathy voice) best distinguishes the voiced aspirates in production. In perception, listeners make use of all cues, in line with production patterns. Tokens in which concurrent prevoicing and aspiration are categorically identified as voiced aspirates, indicating that the joint presence of these two cues is sufficient for voiced stop identification and demonstrating the primacy of these features over all of the others tested. At the same time, neither prevoicing nor aspiration is strictly necessary for voiced aspirate identification; a stop token be perceived as a voiced aspirate even when one of these is absent, as long as the breathy voice quality also characteristic of voiced aspirates is present. We attribute the disproportionately large perceptual category space for voiced aspirates to the variability of voiced aspirates in production.