Relations between vocal registers in voice breaks

1783 modal-falsetto register breaks and 853 falsetto-modal register breaks, produced by seven untrained adult male subjects, were recorded and analyzed with respect to jumps in fundamental frequency and sound pressure level (SPL) using a computer phonetograph. SPL and relative positions of modal and falsetto registers were the most important factors underlying the results. Whereas subor supraglottal coupling certainly cannot explain the results, models of intrinsic nonlinear behavior of the vocal folds may need to be extended for explanations of breaks outside the overlap area of the two registers.