Purpose: Translating exercise-science methodology for determination of muscle bioenergetics, we hypothesized that the temporal voice-use patterns for classroom and music teachers would indicate a reliance on the immediate energy system for laryngeal skeletal-muscle metabolism. It was hypothesized that the music-teacher group would produce longer voiced segments than the classroom teachers. Method: Using a between- and within-group multivariate analysis-of-variance design (5 classroom teachers; 7 music teachers), we analyzed fundamental-frequency data--collected via an ambulatory phonation monitor--for length (seconds) of voiced and nonvoiced intervals. Data were collected for 7.5 hr during the workday, over the course of several workdays for each teacher. Results: Descriptive analyses of voiced and nonvoiced intervals indicated that over 99% of voiced segments for both groups were no longer than 3.15 s, supporting the hypothesis of reliance on the immediate energy system for muscle bioenergetics. Significant differences were identified between and within the classroom- and music-teacher groups, with the music-teacher group producing longer voiced segments overall. Conclusions: Knowledge of probable intrinsic laryngeal skeletal-muscle bioenergetics requirements could inform new interdisciplinary considerations for voice habilitation and rehabilitation.