Pitch accent timing and scaling in Chickasaw

Questions in Chickasaw, an endangered Muskogean language of Oklahoma, display a transition from a high pitch accent (H*) to a low boundary tone (L%) within a three-syllable window at their right edge. The location of H* has been reported to be sensitive to the weight of the final three syllables. It falls on the final syllable if it contains a long vowel. If the final syllable has a short vowel, the pitch accent falls on a heavy penultimate syllable (CVV or CVC), and otherwise on the antepenultimate syllable. Phonetic investigation of the timing and scaling of the pitch accent in the production of Chickasaw questions by three speakers confirms these phonological patterns, but also reveals considerable variability across speakers and accent locations in phonetic aspects of pitch accent realization. H* occurs progressively earlier in accented syllables the closer the syllable is to the end of the question. This leftward shifting of the pitch accent may be viewed as an instance of tonal repulsion attributed to crowding of H* and L%. Final vowels, which support both H* and L%, are not lengthened and scaling effects on H* and L% are less consistent across speakers, suggesting that the primary means for minimizing tonal crowding in Chickasaw is through timing changes in the location of the pitch accent rather than other means such as tonal undershoot or segmental lengthening.