Devoicing of Word-initial Stops: a Consequence of the following Vowel?

The aim of the current study is to investigate the contextual conditions of devoicing of phonologically voiced stops (bilabial and velar). Articulatory and acoustic data from four male speakers were recorded by means of EMMA and EPG. Devoicing was observed more frequently for the velar stops than for the bilabials. The highest occurrence of devoicing was observed when the voiced stop was followed by a low or mid-vowel. To test whether articulatory positions are affected by the identity of the following vowel ANOVAs were computed. All subjects showed significant effects on positional data varying with place of articulation of the stop. Percentage of devoicing was significantly correlated with vertical and horizontal tongue positions for the velar and with the vertical jaw position for both stops. Stepwise regression models were computed to achieve an objective measure of the relevance of the measured parameters. We assume that in German, movement economy, i.e., co-articulation is more important than the maintenance of voicing during the closure, which is in agreement with the view that the voicing distinction in German is primarily produced by a longer VOT for the voiceless stops.