Audio Engineering Society Convention Paper Presented at the 135th Convention 2013 October 17–20 New York, USA This paper was peer-reviewed as a complete manuscript for presentation at this Convention. Additional papers may be obtained by sending request and remittance to Audio Engineering Society, 60 East 42 nd Street, New York, New York 10165-2520, USA; also see www.aes.org. All rights reserved. Reproduction of this paper, or any portion thereof, is not permitted without direct permission from the Journal of the Audio Engineering Society. Maximum Averaged and Peak Levels of Vocal Sound Pressure Braxton Boren, 1 Agnieszka Roginska, 1 and Brian Gill 1 1 New York University, New York, NY, 10012, USA Correspondence should be addressed to the authors ({bbb259, roginska, brian.gill}@nyu.edu) ABSTRACT This work describes research on the maximum sound pressure level achievable by the spoken and sung human voice. Trained actors and singers were measured for peak and averaged SPLs at an on-axis distance of 1 m at three different subjective dynamic levels and also for two different vocal techniques (‘back’ and ‘mask’ voices). The ‘back’ sung voice was found to achieve a consistently lower SPL than the ‘mask’ voice at a corresponding dynamic level. Some singers were able to achieve high averaged levels with both spoken and sung voice, while others produced much higher levels singing than speaking. A few of the vocalists were able to produce averaged levels above 90 dB A , the highest found in the existing literature. 1. INTRODUCTION Ongoing research has sought to estimate the sound pressure level (SPL) of the 18th century Anglican preacher George Whitefield, based on an auditory experiment conducted by Benjamin Franklin in 1739 [1]. That work has so far yielded estimates of White- field’s averaged SPL at 1 m greater than 90 dB A . Much of the existing literature on maximum vocal SPL has used different measurement methods at dif- ferent distances, and few of these studies have exam- ined the maximum long-term L eq , which describes the voice’s average pressure over time and is often used as a substitute for steady-state pressure in a varying acoustic system such as speech or song. In addition, research into vocal directivity patterns has examined the impact of changing vocal reso- nances for a single vocalist [2]. Though change in vocal resonance was not found to have a significant effect on acoustic radiation pattern, some vocalists believed that certain vocal placements were more ef- fective at reaching an audience than others. It was hypothesized that this was because different vocal resonances might correspond to differences in over- all sound pressure rather than directivity. Absolute SPLs of subjective dynamic levels measured in a con- trolled environment could examine this theory fur- ther. From an audio engineering perspective, the maxi- mum peak and average SPLs of trained vocalists are important because training can significantly increase