The project of this thesis consists in several chronological stages: the first (July 2014) related classroom acoustics characterization. The second (November/December 2014) focused on teachers' voice monitoring over several working days during their teaching activity, and noise level measurements during lessons. During the third stage (February/March 2015) a seminar was held in each school for the students who would later completed the subjective questionnaires. The fourth stage (April/May 2015) consists in repeating the teachers' voice monitoring and noise level measurements in order to investigate if there are statistically significant differences in the parameters acquired at the beginning and at the end of the school year.

In-field measurements related sound insulation and room acoustics parameters. As far as sound insulation is concerned, the sound reduction index between adjacent and overlapped rooms, standardized noise level difference value of facade and maximum weighted standardized impact sound pressure level were measured in one in representative classroom in each school.

Room acoustical parameters were measured in occupied and unoccupied conditions for classrooms with different acoustical treatment in Avogadro institute, and for three classrooms with single, medium and double volume in Maxwell institute. Reverberation time and clarity were measured accordingly to the ISO 3382 standard using the B&K 4128 HaTS as a sound source. For clarity only one combination source-receiver position was considered.

Room gain and voice support were taken from literature and measured in two different positions in the room, while speech transmission index was measured considering the same source-receiver position assumed for clarity, with the indirect method reported in the IEC 60268-16.

Vocal load of teachers over several working days was monitored by means of the Voice-Care device, recently developed at the Politecnico di Torino. Mean and mode sound pressure level and fundamental frequency, as well as phonation time percentage were obtained for each teacher's monitoring.

Background noise was measured along the entire teachers' voice monitoring allowing the different teaching activities and subjects to be classified in terms of background noise level.

Surveys on the subjective impression of acoustical comfort in classrooms were administered to teachers and students. Subjective perception of teachers regarded noise disturbance, vocal effort and reverberation after each monitoring and averagely across the overall teaching period. Students were asked to rate subjective impressions on noise disturbance, teachers' vocal effort, reverberation, speech intelligibility and overall acoustical quality. All the objective data (acoustics characteristics, teachers' vocal effort and background noise level) are in this thesis analyzed in relation with the subjective data using statistical tools.

The objective of this thesis is the investigation of the relations between objective and subjective perception of acoustic conditions in high school classrooms. In particular, the level of noise measured in different environments during different activities, the vocal effort of teachers, the subjective impression of teachers and students and the physical and acoustical characteristics of classrooms are hereby put in relation.

The outcomes of this analysis are willing to help in the definition of new acoustical requirements for classrooms design, in particular for integration with the existing protocols such as LEED for SCHOOL. The minimum requirements, indeed, now only refer to sound absorption and reduction of noise level. It would therefore be appreciable to add enhanced requirements referred to subjective parameters in relation to objectively measured parameters. This would help in the design of school environments that ensure a high level of teaching and learning quality for both students and teachers.

2. Green Building Labels and the relevance of acoustic performance

Part II

1. Parameters of acoustical quality

2. Vocal parameters monitoring

Part III

1. Case studies

2. Objective data

2.1 Acoustic characterization of school building

2.2 Voice and background noise level monitoring

3. Subjective data

3.1 Teachers' and students’ questionnaires

3.2 Participants

Part IV

1. Questionnaires

2. Statistical analyses

3. Results

3.1 Overall environmental quality perception

3.2 Acoustical quality perception for students and teachers

3.3 Reverberation

3.4 Intelligibility

3.5 Teachers’ sound pressure level, background noise level and teachers’ perception of vocal effort

3.6 Disturbance of noise and measured level of noise

3.7 Consequences caused by poor acoustics

DISCUSSIONS

CONCLUSIONS

BIBLIOGRAPHY

- A. Astolfi, A. Carullo, L. Pavese, G. E. Puglisi, "Valutazione del carico vocale degli insegnanti di scuola primaria, secondaria e dell'infanzia tramite il dispositivo voice-care®, dei fattori acustici di influenza e delle ripercussioni sulla salute vocale", Politecnico di Torino, Maggio 2014

- A. Astolfi, V. Corrado, A. Griginis, "Comparison between measured and calculated parameters for the acoustical characterization of small classrooms", Applied Acoustics, n. 69, 2008

- A. Astolfi, M. Filippi, A. Griginis "Interventi di riqualificazione acustica delle aule scolastiche", 35° Convegno nazionale AIA, Milan, 2008

- A. Astolfi, M. Giovannini, "Acustica delle aule scolastiche: requisiti prestazionali, soluzioni di progetto, verifiche a calcolo e in opera", Rockwool,

2010

- A. Astolfi and F. Pellerey, "Subjective and objective assessment of acoustical and overall environmental quality in secondary school classrooms", Journal of Acoustic Society of America, January 2008

- A. Astolfi, G. E. Puglisi, L. Pavese, A. Carullo, "Long-term vocal parameters of primary school teachers and classroom acoustics with and without an acoustical treatment", European Acoustics Association, Forum Acusticum, September 2014

- P. Barrett, Y. Zhang, J. Moffat, K. Kobbacy, "A holistic, multi-level analysis identifying the impact of classroom design on pupils' learning", Building and Environmental, n. 59, 2013

- S. Bao, E. F. Chang, J. D. Davis, K. T. Gobeske, M. M. Merzenich, "Progressive degradation and subsequent refinement of acoustic representations in the adult auditory cortex", The Journal of Neuroscience, 26 November 2003

- E. Benson, "Aircraft noise impairs children's reading and memory", American Psychological Association, vol. 33, n. 11, December 2002

- P. Bottalico, A. Astolfi, "investigation into vocal doses and parameters pertaining to primary school teachers in classrooms", Journal of Acoustic Society of America, April 2012

- J. S. Bradley, "Acoustical design of rooms for speech", Institute for research in construction, March 2002

- J. S. Bradley, "Speech intelligibility studies in classrooms", Journal of Acoustic Society of America, September 1986

- J. S. Bradley, H. Sato, "The intelligibility of speech in elementary school classrooms", Journal of Acoustic Society of America, April 2008

- A. L. Bronzaft, "A quieter school: an enriched learning environment"

- A. Carullo, A. Astolfi, "Voice-care: un dispositivo per il monitoraggio vocale dei professionisti della voce"

- Carullo et al.

- Circolare del Ministero dei Lavori Pubblici del 22/05/67 n. 3150, "Criteri di valutazione e collaudo dei requisiti acustici negli edifici scolastici"

- D. M. Connolly, J. E. Dockrell, B. M. Shield, R. Conetta, T. J. Cox, "Students' perceptions of school acoustics and the impact of high noise on teaching and learning in secondary schools: finding of a questionnaire survey", 6th International Building Physics Conference, IBPC 2015

- T. Cox, "James report under fire for failure", Acoustics Bulletin, July/August

2011

- V. De Giuli, 0. Da Pos, M. De Carli, "Indoor environmental quality and pupil perception in Italian primary schools", Building and Environment, n. 56, 2012

- Departement for education and skills, BUILDING BULLETIN 93, "Acoustic design of schools: a design guide", London: the Stationery Office, 2003

- Departement for education and skills, "Acoustic performance standards for the priority schools building programme", London: the Stationery Office, 2013

- DIN 18041, "Acoustical quality in small to medium-sized rooms", DEU, 2004

- F. Dolozal, C. Spitzbart-Glasl, "Relevance of acoustic performance in Green Building Labels and Social Sustainability Ratings", 6th International Building Physics Conference, IBPC 2015

- DPCM 14/11/97, "Determinazione dei valori limite delle sorgenti sonore", in G.U. n. 280 del 1/12/97

- DPCM 5/12/1997, "Determinazione dei requisiti acustici passive degli edifici", in G.U. n. 297 del 22/12/97

- S. Fasolis, V. Lorenzatti, "The Green School project: classrooms acoustics and vocal load of teachers in high-schools, Maxwell and Avogadro Institutes", tesi di Laurea, Politecnico di Torino, Dicembre 2014

- M. Filippi, E. Sirombo, "Green rating of existing school facilities", 6th

International Building Physics Conference, IBPC 2015

- Green Building Council Italia, "LEED per le scuole", IT, 2009

- P. J. Harght, "An investigation on classroom acoustics for non-green and

green classrooms", December 2008

- International standard ISO 9921, "Ergonomics-assessment of speech communication", 2003

- S Kempe, C. Hofle, J. Gorres, H. Erhorn-Kluttig, H. Erhorn, H.M. Beckert, "School of the future: deep renovation of the Solitude-Gymanasium in Stuttgart", 6th International Building Physics Conference, IBPC 2015

- S. M Kennedy, M. Hodgson, L. D. Edgett, N. Lamb, R. Rempei, "Subjective assessment of listening environments in university classrooms: perceptions of students", Journal of Acoustic Society of America, January 2006

- S. B. King, "Classroom Acoustics: What are Texas Architects saying?", publication on American Speech-Language-Hearing Association's website

- J. Kristiansen, S. P. Lund, P. M. Nielsen, R. Persson, H. Shibuya, "Determinants of noise annoyance in teachers from schools with different classrooms reverberation times", Journal of Environmental Psychology, n. 31, 2011

- E. L. Kruger, P. H. T. Zannin, "Acoustics, thermal and luminous comfort in classrooms", Building and Environment, n. 39, 2004

- L. Loreti, L. Barbaresi, S. De Cesaris, M. Garai, "Overall indoor quality of a non-renewed secondary-school building", 6th International Building Physics Conference, IBPC 2015

- D. Mumovic, J. Palmer, M. Davies, M. Orme, I. Ridley, T. Oreszczyn, C. Judd, R. Critchlow, H. A. Medina, G. Pilmoor, C. Pearson, P. Way, "Winter indoor air quality, thermal comfort and acoustic performance of newly built secondary school in England", Building and Environment, n. 44, 2009

- C. Munier, R. Farrell, "Working conditions and workplace barriers to vocal health in primary school teachers", Journal of Voice, 2015

- C. A. Mydlarz, R. Conetta, D. Connoly, T. J. Cox, J. E. Dockrell, B. Shield, "Relationship between room acoustics and environmental parameters", UK,

2012

- C .A. Mydlarz, R. Conetta, D. Connolly, T. J. Cox, J. E. Dockrell, B. M. Shield, "Comparison of environmental and acoustic factors in occupied school classrooms for 11-16 year old students", Building and Environment, n. 60, 2013

- A. Novotney, "Silence, please", American Psychological Association, vol. 42, n. 7, 2011

- F. Ortalda, "The Survey in Psychology", Carocci, Roma, 1998

- D. Pelegrin García, "The role of classroom acoustics on vocal intensity regulation and speakers' comfort", PhD thesis, September 2011

- D. Pelegrin García, J. Brunskog, "Speakers' comfort and voice level variation in classrooms: Laboratory research", Journal of Acoustic Society of America, July 2012

- D. Pelegrin García, J. Brunskog, V. Lyberg-Ahlander, A. Lofqvist, "Measurement and prediction of voice support and room gain in school classrooms", Journal of Acoustic Society of America, 2012 Z. E. Peng, "Designing acoustics for linguistically diverse classrooms: effects of background noise, reverberation and talker foreign accent on speech comprehension by native and non-native English-speaking listeners", December 2014

- G. E. Puglisi, L. C. Cantor Cutiva, L. Pavese, A. Castellana, M. Bona, S. Fasolis, V. Lorenzatti, A. Carullo, A. Burdorf, A. Astolfi, "Acoustic comfort in high- school classrooms for students and teachers", 6th International Building Physics Conference, IBPC 2015

- A. Ricci Maccarini, F. Ottaviani, A. Schindler, D. Casolino, "La valutazione percettiva della voce"

- Rosemberg, "Classroom acoustics. Seminars in hearing", American Academy of Audiology, 02 September 2010

- H. Sato, J. S. Bradley, M. Morimoto, "Using listening difficulty ratings of conditions for speech communication in rooms", Journal of Acoustic Society of America, March 2005

- F. Scamoni, C. Scrosati, "The façade sound insulation and its classification", European Acoustics Association, Forum Acusticum, September 2014

- B. Shield, R. Conetta, J. Dockrell, D. Connoly, T. Cox, C. Mydlarz, "A survey of acoustic conditions and noise levels in secondary school classrooms in England", Journal of Acoustic Society of America, January 2015

- B. M. Shield, J. E. Dockrell, "La necessità di una buona acustica nelle aule scolastiche", 2011

- B. M. Shield, J. E. Dockrell, "The effects of noise on children at school: a review", Journal Building Acoustics 10(2), 2003

- P. H. Trombetta Zannin, C. Reich Marcon, "Objective and subjective evaluation of acoustic comfort in classrooms", Applied Ergonomics, n. 38, 2007

- UNI EN ISO 3382-2, "Misurazione dei parametri acustici degli ambienti, tempo di riverberazione negli ambienti ordinari", 2008

- UNI 11367/2010, "Acustica in edilizia. Classificazione acustica delle unità immobiliari. Procedura di valutazione e verifica in opera", IT (2010)

- UNI EN ISO 10052, "Misurazioni in opera dell'isolamento acustico per via aerea, del rumore da calpestio e della rumorosità degli impianti", 2010

- UNI EN ISO 28802, "Valutazione di ambienti mediante un'indagine ambientale che include sia misurazioni fisiche dell'ambiente sia le risposte soggettive delle persone", July 2012

- WORLD HEALTH ORGANIZATION, "Guidelines for community noise", 1999