Constraints on variability in the voice onset time of L2 English stop consonants

Non-native speech production is frequently characterized by its deviation from native pronunciation. Among segments, previous work has largely focused on describing the separation between native and non-native speakers at the level of individual phonetic categories. An additional hallmark of L1 pronunciation is the presence of systematic relationships within and among phonetic categories. For example, mean voice onset times (VOT) strongly covary among aspirated stop consonants across L1 speakers of American English. The present study examined whether L2 English speakers from various L1 backgrounds differ from native speakers in the relationship of VOT among word-initial /ptk/. Despite differences in the overall realization, L2 speakers resembled native English speakers in the degree of VOT covariation between stop-specific means and variances, as well as between /ptk/. These findings have important implications for the perception of accented speech, as listeners could employ structured relationships to facilitate adaptation despite non-native realizations of individual phonetic categories.