TITLE:
Intelligibility of Reverberant Speech with Amplification: Limitation of Speech Intelligibility Metrics, and a Preliminary Examination of an Alternative Approach
AUTHORS:
Doheon Lee, Eunju Gong, Densil Cabrera, Manuj Yadav, William L. Martens
KEYWORDS:
Speech Intelligibility, Speech Level, Room Reverberation, Loudness
JOURNAL NAME:
Journal of Applied Mathematics and Physics,
Vol.3 No.2,
January
30,
2015
ABSTRACT: 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 (EDTN and TN). 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. EDTN and TN 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.