Voice source differences between registers in female musical theater singers.

Musical theater singing typically requires women to use two vocal registers. Our investigation considered voice source and subglottal pressure P(s) characteristics of the speech pressure signal recorded for a sequence of /pae/ syllables sung at constant pitch and decreasing vocal loudness in each register by seven female musical theater singers. Ten equally spaced P(s) values were selected, and the relationships between P(s) and several parameters were examined; closed-quotient (Q(closed)), peak-to-peak pulse amplitude (U(p-t-p)), amplitude of the negative peak of the differentiated flow glottogram, ie, the maximum flow declination rate (MFDR), and the normalized amplitude quotient (NAQ) [U(p-t-p)/(T0*MFDR)], where T0 is the fundamental period. P(s) was typically slightly higher in chest than in head register. As P(s) influences the measured glottogram parameters, these were also compared at an approximately identical P(s) of 11 cm H2O. Results showed that for typical tokens, MFDR and Q(closed) were significantly greater, whereas U(p-t-p) and therefore NAQ were significantly lower in chest than in head.