The singleton-geminate distinction can be rate dependent: Evidence from Maltese

Many languages distinguish short and long consonants, or singletons and geminates. The primary acoustic correlate of this distinction is the duration of the consonants. Given that the absolute duration of speech sounds varies with speech rate, the question rises to what extent the category boundary between singletons and geminates is sensitive to the overall speech rate (i.e., rate normalization). Next to rate normalization, there are two other possible explanations how singletons and geminates might be distinguished. First, it has been suggested that despite variation in absolute duration, the two categories remain distinct; that is, even in fast speech, geminates seldom take on durations that would be typical of singletons at slow speech rates. Second, it has been suggested that, with higher speech rate, both the duration of consonants and vowels shrink, so that the duration ratio of consonant and adjacent vowel is a rate independent cue for the singleton-geminate distinction. Using production and perception data from Maltese, we show that, first, the singleton-geminate distinction is endangered by speech-rate variation and, second, consequently undergoes speech-rate normalization.