New York

Acoustic Characteristics of Vocal Sounds Used by Professional Actors Performing Classical Material
without Microphones in Outdoor Theatre

Joan Melton, PhD, Zachary Bradford, and Jessica Lee


Results suggest that, along with vocal loudness, fundamental frequency range, the Actor’s Formant, articulation, and movement contribute to the successful performance of classical material in outdoor theatre. Character, style, and timing are also essential, and in venues like Central Park, intelligibility is critical. Acoustic strategies for communicating across distance appear to be different for male and female actors, though additional investigation is needed in this regard. Specifics of voice function, for example, tend to be worked out in the environment, so feedback from the actors themselves could prove highly valuable. Although the current study used an actual theatre space for data collection, sounds experienced in a live performance are uniquely influenced by where audience members are positioned in relation to the performers. Therefore, a follow-up perceptual study from a range of distances may provide additional details regarding vocal sounds that carry well and communicate effectively with audiences in outdoor environments.


Objective: Theatre actors use voice in virtually any physical position, moving or still, and perform in a wide range of venues. The present study investigated acoustic qualities required to perform classical material without electronic amplification in outdoor spaces..

Design: Eight professional actors, four female, four male, from NY Classical Theatre performed one-minute monologues, first stationary, then moving, for audio recording in Central Park. Four subjects recorded two monologues each, from productions in which they played both male and female characters. Data were analyzed for fundamental frequency (F0), sound pressure level (SPL), and long-term average spectrum (LTAS).

Results: Overall, F0 ranged between 75.38 and 530.33 Hz. Average F0 was 326 Hz stationary and 335.78 Hz moving for females, 248.54 Hz stationary, 252.82 Hz moving for males. SPL ranged from 28.54 to 110.51 dB for females, and 56.69 to 124.44 dB for males. Average SPL was 82 dB for females, 96.98 dB for males. On LTAS, females had a peak between 3 to 4 kHz ranging from 1.5 to 4.5 dB and another between 4 to 5 kHz ranging from 1 to 4.5 dB, while males had a peak between 3 to 4 kHz ranging from 1 to 8.5 dB.

Conclusions: Actors appear to use a similar F0 range across gender and performing conditions. Average F0 increased from stationary to moving. Males had greater SPL values than females,
and the amplitude of peaks in the region of the Actor’s Formant of LTAS curves was higher in male than female voices.

Acknowledgement: Sincere thanks to Johan Sundberg, PhD, Research Advisor for Data Analysis and Study Design

Video editing by Jessica Lee and Christopher Wahlmark, PowerPoint by Zachary Bradford