Compensation of F0 and formant frequencies in a real-time pitch-perturbation paradigm

While producing speech, talkers monitor both somatosensory and auditory feedback. Many studies have demonstrated that if auditory feedback is manipulated in real-time (e.g., using an effects processor to shift the frequency spectrum), subjects compensate by modifying their F0 in the direction opposite to the perturbation. However, shifting the entire frequency spectrum alters both F0 and formant frequencies. While compensations for real-time formant perturbations have been previously observed, these studies have used a paradigm that is very different from that of traditional pitch-perturbation experiments. In the present study, compensations in both F0 and formant frequencies were compared for perturbations of sustained vowels using a traditional pitch-perturbation paradigm. Within a sustained utterance, the auditory feedback was shifted by a constant magnitude for a short duration. Previous studies have suggested that the large variability in compensation across individuals may be due to individual differences in weighting somatosensory and auditory feedback. Following this hypothesis, individuals’ compensations in F0 and formant frequency should be correlated. Results from the present experiment are discussed in this context and formant compensations are compared to results from experiments using a traditional formant-perturbation paradigm.