Perturbation of voice signals in register transitions on sustained frequency in professional tenors.

PURPOSE: Vocal register transitions in the passaggio region remain an unclarified field in classically trained male singers.
METHOD: We examined the acoustic and electroglottographic signals of seven tenors' transitions from voix mixte to falsetto on a sustained pitch F4 (349Hz) on the vowels /a, e, i, o, u, and æ/.
RESULTS: It was found that in many of the tested subjects, register transitions between voix mixte and falsetto were performed very continuously without clear register transition events. However, an increase of frequency and amplitude perturbation (jitter, relative average perturbation, and shimmer) was observed during register transitions.
CONCLUSION: These data suggest that professional tenors are able to avoid sudden registration events frequently observed in untrained voices.