Experimental protocol for the evaluation of speech intelligibility in classrooms, equipped with PA systems, of the University of Bologna heritage buildings.

Journal title RIVISTA ITALIANA DI ACUSTICA
Author/s Matteo Spinelli, Luca Barbaresi, Alessia Nora, Virginia Tardini
Publishing Year 2025 Issue 2025/2
Language Italian Pages 10 P. 45-54 File size 0 KB
DOI 10.3280/riaof-2025oa19516
DOI is like a bar code for intellectual property: to have more infomation click here

View article Download Open Access article

FrancoAngeli is member of Publishers International Linking Association, Inc (PILA), a not-for-profit association which run the CrossRef service enabling links to and from online scholarly content.

There is well-established scientific literature on acoustic parameters and indicators suitable for describing the quality of educational environments and in particular university classrooms. The acoustics of a room depends on geometric and architectural features, the arrangement of materials, and, if present, the amplification system. The latter component is rarely considered in the design phase, but it is crucial to ensure acoustic comfort in large classrooms. The paper presents the elaboration of a protocol, developed during the measurement of 17 classrooms at the University of Bologna. The purpose is the analysis of the electroacoustic systems present within the university's classrooms. The results show that only a minority of them comply with speech intelligibility requirements. The protocol turns out to be a useful tool for the evaluation of large teaching halls, with respect to the planning of electroacoustic system upgrades.

Keywords: speech intelligibility;public address systems;acoustic of university classrooms

  1. Hodgson, M., R. Rempel, and S. Kennedy (1999). Measurement and prediction of typical speech and background-noise levels in university classrooms during lectures. The Journal of the Acoustical Society of America 105 (1), 226–233. DOI: 10.1121/1.424600
  2. Pelegrin-Garcia, D., B. Rasmussen, and J. Brunskog (2014). Classroom acoustics design for speakers’ comfort and speech intelligibility: a european perspective. In Proceedings of Forum Acusticum 2014.
  3. Pelegrín-García D, Brunskog J, Lyberg-Åhlander V, Löfqvist A. Measurement and prediction of voice support and room gain in school classrooms. J Acoust Soc Am. 2012 Jan;131(1):194-204. DOI: 10.1121/1.3665987
  4. Wijngaarden, S.J., Van, Steeneken, H.J.M. and Houtgast, T. (2002). Quantifying the intelligibility of speech in noise for non-native listeners, J. Acoust. Soc. Am, DOI: 10.1121/1.1456928
  5. ISO 3382-2 Acoustic: Measurement of room acoustic parameters - Part 2 Reverberation time in ordinary rooms.
  6. IEC 60268-16: Sound system equipment - Part 16: Objective rating of speech intelligibility by speech transmission index.
  7. UNI 11532-2 Acustica in edilizia - Caratteristiche acustiche interne di ambienti confinati - Metodi di progettazione e tecniche di valutazione - Parte 2: Settore scolastico.
  8. D'Orazio, D., Fratoni, G., & Tardini, V. (2025). The Italian standard on classroom acoustics UNI 11532-2: 2020 explained through case studies. Applied Acoustics, 231, 110498. DOI: 10.1016/j.apacoust.2024.110498
  9. Fratoni, G., De Salvio, D., Tardini, V., Garai, M., Valdiserri, P., Biserni, C., & D’Orazio, D. (2025). Student Activity in Suboptimal Thermal and Acoustic Conditions: An In-Field Study in Active Classrooms. Applied Sciences, 15(6), 3119. DOI: 10.3390/app15063119
  10. De Salvio, D., & D’Orazio, D. (2022). Effectiveness of acoustic treatments and PA redesign by means of student activity and speech levels. Applied Acoustics, 194, 108783. DOI: 10.1016/j.apacoust.2022.108783
  11. Fratoni, G., De Salvio, D., D'Orazio, D., & Garai, M. (2021). Acoustical comfort in university lecture halls: simulating the dynamic role of occupancy. In 17th International Conference of the International Building Performance Simulation Association (BS 2021) (pp. 3704-3711). DOI: 10.3390/app15063119
  12. Steeneken, H.J.M. and Houtgast, T., "Some applications of the Speech Transmission Index (STI) in auditoria", Acustica 51, 1982, p.229-234.
  13. Steeneken, H.J.M. and Houtgast, T., "A physical method for measuring speech transmission quality", J. Acoust. Soc. Amer. 67, 1980, 31, p.318-326.
  14. Houtgast, T. and Steeneken, H.J.M., "The modulation transfer function in room acoustics as a predictor of speech intelligibility", Acustica 28, 1973, p.66-73.
  15. Steeneken, H.J.M. and Houtgast, T., "Mutual dependency of the octave-band weights in predicting speech intelligibility," Speech Communication 28, 1999, p.109-123. DOI: 10.1016/S0167-6393(99)00007-2
  16. Houtgast, Tammo, and Herman JM Steeneken. "A review of the MTF concept in room acoustics and its use for estimating speech intelligibility in auditoria. "The Journal of the Acoustical Society of America 77.3: 1069-1077, 1985.
  17. Steeneken, H.J.M., Verhave, J.A., McManus, S., and Jacob, K.D., (2001) "Development of an Accurate, Handheld, Simple-to-use Meter for the Prediction of Speech Intelligibility", Proceedings IoA 2001, Reproduced sound (17). Stratford-upon-Avon, UK.
  18. CEI EN 61672-1, “Electroacoustics - Sound level meters - Part 1: Specifications”, 2013.
  19. Bradley, John S. Acoustical design of rooms for speech. Ottawa, ON: Institute for Research in Construction, National Research Council of Canada, 2002. DOI: 10.4224/40002824
  20. Murray Hodgson,Case-study evaluations of the acoustical designs of renovated university classrooms,Applied Acoustics,Volume 65, Issue 1,2004,Pages 69-89, DOI: 10.1016/S0003-682X(03)00108-7
  21. Urban, Marcel, Christian Heil, and Paul Bauman. "Wavefront sculpture technology." Journal of the Audio Engineering Society 51.10 (2003): 912-932.
  22. Massaro, D. W., & Warner, D. S. (1977). Dividing attention between auditory and visual perception. Perception & Psychophysics, 21(6), 569-574.
  23. Massaro, D. W., & Simpson, J. A. (2014). Speech perception by ear and eye: A paradigm for psychological inquiry. Psychology Press. DOI: 10.4324/9781315808253
  24. Massaro, D. W., & Palmer Jr, S. E. (1998). Perceiving talking faces: From speech perception to a behavioural principle. Mit Press.
  25. Lalonde, K., Werner, L.A. (2019). Infants and adults use visual cues to improve detection and discrimination of speech in noise. Journal of Speech, Language, and Hearing Research, 62(10), 3860-3875, DOI: 10.1044/2019_JSLHR-H-19-0106

Matteo Spinelli, Luca Barbaresi, Alessia Nora, Virginia Tardini, Protocollo sperimentale per la valutazione dell’intelligibilità del parlato nelle aule, dotate di impianto elettroacustico, del patrimonio edilizio dell’Università di Bologna. in "RIVISTA ITALIANA DI ACUSTICA" 2/2025, pp 45-54, DOI: 10.3280/riaof-2025oa19516