Speech Intelligibility of Lecture Theatres in Obafemi Awolowo University, Ile-Ife, Nigeria
This work measured the speech intelligibility of lecture theatres in Obafemi Awolowo University (OAU), Ile-Ife, Nigeria using the Rapid Speech Transmission Index (RASTI) and Speech Transmission Index for Public Address (STIPA) methods. These methods are objective speech intelligibility measurement methods and they have been used in this work to determine definite and quantitative speech intelligibility values of lecture theatres in OAU unavailable before. RASTI is known to overestimate values when public address systems are involved and this was also observed to be true in this work. STIPA values are therefore recommended for making decisions related to speech intelligibility of the lecture theatres while RASTI values were evaluated for record purposes. Lecture theatres with architectural designs that minimize reverberation in addition to good interior acoustic enhancements were observed to have higher RASTI and STIPA values than lecture theatres with poor architectural design and poor acoustic enhancements.
Garay-Vargas, E. and Rodriguez-Manzo, F.E. “Analysis of the impact of sound diffusion in the reverberation time of an architectural space – A proposal for the characterization of diffusive surfaces using scale model”, Proceedings of Second ASA-EAA Joint Conference (Acoustic ’08 Paris): 4521 – 4526, 2008.
Davis, D. and Patronis, E. “Sound System Engineering”, Elsevier Inc., USA, 2006.
Ballou, G.M. “Handbook for Sound Engineers”, Focal Press, United States, 2002.
Sound Pro Audio Consultant Operational Manual, Firmware Version 1.54, Sencore.
Greenland, E. Shield, B. and Dockrell, J., “Acoustics in open plan classrooms –towards revised speech intelligibility criteria”, Proceedings of the Institute of Acoustics, 31(4): 50-61, 2009.
Leembruggen, G. Hippler, M. and Mapp, P., “Exploring ways to improve STI’s recognition of the effects of poor spectral balance on subjective intelligibility”, Proceedings of the Institute of Acoustics, 31(4): 133-169, 2009.
Bjor, O., “STIPA, The Golden mean between full STI and RASTI”, Proceedings of the Institute of Acoustics, 25(7), 2003.
Nestoras, C. Gomez, L., Dance, S. and Murano, S., “Speech Intelligibility measurements a in diffuse space using open and closed loop systems”,19th International Congress on Acoustics, Madrid, September, 2007.
Zeilstra, G.J., “Speech Intelligibility in Classrooms: A new measurement method”, A Master Thesis Project, Applied Physics, Faculty of Applied Sciences, Delft University of Technology, Holland, 2009.