Prevision of optimal speech intelligibility in primary school classrooms through simulation of optimal acoustic absorption and diffusion conditions

SECTION 1 - STARTING CONCEPTS

1.1 SOUND AS PHYSICAL PHENOMENON

1.1.1 SOUND AND SOURCES

1.2 PARAMETERS

1.2.1 REVERBERATION TIME

1.2.2 CLARITY

1.2.3 DEFINITION

1.2.4 EARLY DECAY TIME

1.2.5 SIGNAL-TO-NOISE RATIO

1.2.6 SPEECH TRANSMISSION INDEX

1.2.7 EQUIVALENT NOISE LEVEL

1.3 ACOUSTICS AS AN INTERDISCIPLINARY SCIENCE

1.4 LISTENING TASK

1.4.1 HUMAN HEARING SYSTEM

1.4.2 SOUND PERCEPTION

1.4.3 SPEECH INTELLIGIBILITY AND LISTENING EFFORT

1.4.4 COCKTAIL PARTY PHENOMENON

1.4.5 ADVANTAGES FROM BINAURAL LISTENING

SECTION2 - ACOUSTIC COMFORT

2.1 ACOUSTICS IN TEACHING ENVIRONMETS

2.1.1 SOURCES OF NOISE AND RELATED EFFECTS

2.1.2 VOCAL EFFORT AND RELATED ILLNESSES

2.2 ACOUSTIC REQUIREMENTS

2.2.1 LEGISLATION

2.3 DESIGN SOLUTIONS TO CONTROL NOISE

2.3.1 CONTROL OF EXTERNAL NOISES

2.3.2 CONTROL OF INTERNAL NOISES

2.3.3 ACOUSTIC BRIDGES AND INSTALLATIONS

2.4 DESIGN SOLUTIONS TO CONTROL REVERBERATION

2.4.1 SOLUTIONS AND MATERIALS FOR SOUND ABSORPTION

SECTION 3 - EXPERIMENTATION

3.1 COOPERATION WORK WITH OLDENBURG

3.2 RESEARCH PROPOSALS

3.2.1 CASE STUDY AND FEATURES

3.2.2 ROOM A

3.2.3 ROOM B

3.2.4 INVESTIGATION

3.2.5 CONFIGURATIONS

3.3 STEP ONE: LISTENING TEST

3.3.1 THE MATRIX SENTENCE TEST

3.3.2 SETTINGS

3.3.3 TEST RESULTS

3.4 STEP TWO: MODEL CALIBRATION

3.4.1 DIGITAL MODELS FOR REAL CLASSROOMS

3.4.2 SURFACES' PROPERTIES

3.4.3 CALIBRATION RESULTS

3.4.4 COMMENTS ON CALIBRATION

3.5 STEP THREE: ACOUSTIC DESIGN

3.5.1 FLAWS IN COMMON TREATMENTS

3.5.2 ANALYSIS SPECIFICATIONS

3.5.3 THE DIFFUSING PANEL ON THE LOWER FRONT WALL: COMPARISONS

THE LAST RAW OF SEATS

3.5.4 TOWARDS THE BEST IMPROVEMENT

CHOSEN CONFIGURATION

3.6 STEP FOUR: INTELLIGIBILITY PREDICTION

3.6.1 BSIM: A MODEL TO PREDICT INTELLIGIBILITY

3.6.2 BSIM PREDICTION IN THE ROOM BEFORE TREATMENT

3.6.3 BSIM PREDICTION IN THE ROOM AFTER TREATMENT

CONCLUSION

APPENDIX A

APPENDIX B

BIBLIOGRAPHY

ACKNOWLEDGMENTS

Astolfi A., Corrado V., Griginis A.; “Comparison between measured and calculated Parameters for the acoustical characterization of small classrooms”, Applied Acoustics (2008);

Astolfi A., Pellery F., “Subjective and objective assessment of acoustical and overall environmental quality in secondary school classrooms”, JASA (2008);

Barron M. “Auditorium acoustics and architectural design”, 2nd ed. London: E &FN Spon (2009);

Bradley JS, “Speech intelligibility studies in classrooms”, J Acoust Soc Am (1 986);

Bradley JS, “Reich R, Norcross SG. On the combined effects of signal-to-noise ratio and room acoustics on speech intelligibility”. J Acoust Soc Am (1 999);

Bradley JS, Sato H, Picard M. “On the importance of early reflections for speech in rooms”, J. Acoust. (2003);

British standard 8233:1 999, “Sound insulation and noise reduction for buildings - code of practice” (1 999);

Bronkhorst, “The cocktail party phenomenon: a review of research on speech intelligibility in multi-talker condition”, Acta (2000);

Bronzaft A.L. and McCarthy D.P., “The effect of elevated train noise on reading ability”, Environment and Behavior (1 975);

Cherry E. C., “Some experiments on the recognition of speech with one and with two ears”. Journal of the Acoustical Society of America (1 953);

Choi Y., “Effects of periodic type diffusers on classroom acoustics”, Applied acoustics 74 (2013);

Choi Y., “Experimental investigation of the combination of absorptive and diffusive treatments in classrooms” (2015);

Commins D., “Survey of UK voice clinics 2001/2 (2002)”. Voice Care Network UK (2002);

Department for Education and Skills, Building Bulletin 93, “Acoustic Design of School”, London: Stationery Office (2003);

Hygge S., Evans G.W. and Bullinger M., “The Munich Airport noise study: Cognitive effects on children from before to after the change over of airports", Proceeding of internoise ‘96 (1996);

Kidd, G., Mason, C. R., Richards, V. M., Gallun, F. J., and Durlach, “Informational masking in Auditory Perception of Sound Sources” N. I. (2008);

Kob M., Behlery G., Kamprolfz A., Goldschmidtx O., Neuschaefer-Rube C., “Experimental investigations of the influence of room acoustics on teachers’ voice”, Acoust. Sci. & Tech. (2008);

Leijska V., “Occupational voice disorders in teachers”, Pracovini Lekarstvi 19(1 967); Lindsey R. B., “Wheel of acoustics” in J. Acoust. (1 964);

Loreti L., Barbaresi L., D’Orazio D., Garai M., “La percezione del parlato all’interno dell’aula magna della facolta di ingegneria di Ravenna: caratterizzazione ed interventi migliorativi”, AIA (201 6);

Oliaro P., “Rumore degli impianti tecnologici”, in Manuale di acustica applicata (2007);

Pamphlet WHO, Regional Office for Europe, n.38, Noise in Schools (2001);

Puglisi G. E., Warzybok A., Hochmuth S., Visentin C., Astolfi A., Prodi N. & Kollmeier B.: “An Italian matrix sentence test for the evaluation of speech intelligibility in noise”, International Journal of Audiology (2015);

Rennies et al. “Listening effort and speech intelligibility in listening situations affected by noise and reverberation”, J. Acoust. (2014);

Shield and Dockrell, “The effects of Noise on Children at School: a Review” (2002);

Titze I., Lemke J., Montequin D., “Populations in the U.S. Workforce who rely on Voice as a primary tool of Trade: a preliminary report”, The journal of voice 11(1997).