Author(s)

Doheon Lee^*, Eunju Gong, Densil Cabrera, Manuj Yadav, William L. Martens

The Faculty of Architecture, Design and Planning, The University of Sydney, Sydney, Australia.

This study examines the effect of speech level on intelligibility in different reverberation conditions, and explores the potential of loudness-based reverberation parameters proposed by Lee et al. [J. Acoust. Soc. Am., 131(2), 1194-1205 (2012)] to explain the effect of speech level on intelligibility in various reverberation conditions. Listening experiments were performed with three speech levels (LAeq of 55 dB, 65 dB and 75 dB) and three reverberation conditions (T₂₀ of 1.0 s, 1.9 s and 4.0 s), and subjects listened to speech stimuli through headphones. Collected subjective data were compared with two conventional speech intelligibility parameters (Speech Intelligibility Index and Speech Transmission Index) and two loudness-based reverberation parameters (EDT_N and T_N). Results reveal that the effect of speech level on intelligibility changes with a room’s reverberation conditions, and that increased level results in reduced intelligibility in highly reverberant conditions. EDT_N and T_N explain this finding better than do STI and SII, because they consider many psychoacoustic phenomena important for the modeling of the effect of speech level varying with reverberation.

Speech Intelligibility, Speech Level, Room Reverberation, Loudness

Lee, D. , Gong, E. , Cabrera, D. , Yadav, M. and Martens, W. (2015) Intelligibility of Reverberant Speech with Amplification: Limitation of Speech Intelligibility Metrics, and a Preliminary Examination of an Alternative Approach. Journal of Applied Mathematics and Physics, 3, 177-186. doi: 10.4236/jamp.2015.32028.