To promote a fast and effective characterization of the sound environment in small and medium-sized classrooms, a basic measurement protocol, based on a minimum number of parameters and positions, is provided. Measurements were taken in 29 occupied classrooms belonging to 13 primary schools in Turin, Italy, that differ in location and typology. The background noise level was acquired during silent and group activities, and the reverberation time, speech clarity, useful-to-detrimental ratio and speech level, were acquired along the main axis of each classroom and in one or two offset positions. To reduce the number of measured parameters that can be used to fully characterize classroom acoustics, data were divided into two groups on the basis of a cutoff value of maximum occupied reverberation time in the case of moderate and severe requirements. Given the strong correlation among the quantities, thresholds were identified for the other acoustical parameters, and their accuracy and precision were tested to assess their ability to classify the acoustic quality as compliant or non-compliant. Results suggest that more convenient parameters, like clarity in the central position of the classroom, can be used instead of reverberation time to classify classroom acoustics.

1.
A.
Astolfi
,
G. E.
Puglisi
,
S.
Murgia
,
G.
Minelli
,
F.
Pellerey
,
A.
Prato
, and
T.
Sacco
, “
The influence of classroom acoustics on noise disturbance and well-being for first graders
,”
Front. Psychol.
10
,
2736
(
2019
).
2.
G.
Cardon
,
J.
Campbell
, and
A.
Sharma
, “
Plasticity in the developing auditory cortex: Evidence from children with sensorineural hearing loss and auditory neuropathy spectrum disorder
,”
J. Am. Acad. Audiol.
23
(
6
),
396
495
(
2012
).
3.
J.
Stiles
, “
Neural plasticity and cognitive development
,”
Dev. Neuropsychol.
18
(
2
),
237
272
(
2000
).
4.
A. L.
Tierney
and
C. A.
Nelson
, 3rd, “
Brain development and the role of experience in the early years
,”
Zero Three
30
(
2
),
9
13
(
2009
), available at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3722610/.
5.
L. M.
Ronsse
and
L. M.
Wang
, “
Relatioships between unoccupied classroom acoustical conditions and elementary student achievement measured in eastern Nebraska
,”
J. Acoust. Soc. Am.
133
(
3
),
1480
1495
(
2013
).
6.
G. E.
Puglisi
,
A.
Prato
,
T.
Sacco
, and
A.
Astolfi
, “
Influence of classroom acoustics on the reading speed: A case study on Italian second-graders
,”
J. Acoust. Soc. Am.
144
(
2
),
EL144
EL149
(
2018
).
7.
N.
Prodi
,
C.
Visentin
,
E.
Borella
,
I. C.
Mammarella
, and
A. D.
Domenico
, “
Noise, age, and gender effects on speech intelligibility and sentence comprehension for 11- to 13-year-old children in real classroom
,”
Front Psychol.
10
,
2166
(
2019
).
8.
D. L.
Valente
,
H. M.
Plevinsky
,
J. M.
Franco
,
E. C.
Heinrichs-Graham
, and
D. E.
Lewis
, “
Experimental investigation of the effects of the acoustical conditions in a simulated classroom on speech recognition and learning in children
,”
J. Acoust. Soc. Am.
131
(
1
),
232
246
(
2012
).
9.
N.
Prodi
,
C.
Visentin
, and
A.
Farnetani
, “
Intelligibility, listening difficulty and listening efficiency in auralized classrooms
,”
J. Acoust. Soc. Am.
128
(
1
),
172
181
(
2010
).
10.
C.
Visentin
,
N.
Prodi
,
F.
Cappelletti
,
S.
Torresin
, and
A.
Gasparella
, “
Speech intelligibility and listening effort in university classrooms for native and non-native Italian listeners
,”
Build. Acoust.
26
(
4
),
275
291
(
2019
).
11.
N.
Prodi
,
C.
Visentin
,
A.
Peretti
,
J.
Griguolo
, and
G. B.
Bartolucci
, “
Investigating listening effort in classrooms for 5- to 7-year-old children
,”
Lang. Speech Hear. Serv. Sch.
50
(
2
),
196
210
(
2019
).
12.
J. E.
Peelle
, “
Listening effort: How the cognitive consequences of acoustic challenge are reflected in brain and behavior
,”
Ear Hear.
39
(
2
),
204
214
(
2018
).
13.
G. E.
Puglisi
,
A.
Warzybok
,
A.
Astolfi
, and
B.
Kollmeier
, “
Effect of reverberation and noise type on speech intelligibility in real complex acoustic scenarios
,”
Build. Environ.
204
,
108137
(
2021
).
14.
N.
Prodi
,
C.
Visentin
, and
A.
Feletti
, “
On the perception of speech in primary school classrooms: Ranking of noise interference and of age influence
,”
J. Acoust. Soc. Am.
133
(
1
),
255
268
(
2013
).
15.
N.
Prodi
and
C.
Visentin
, “
Listening efficiency during lessons under various types of noise
,”
J. Acoust. Soc. Am.
138
(
4
),
2438
2448
(
2015
).
16.
G. E.
Puglisi
,
L. C.
Cantor Cutiva
,
A.
Astolfi
, and
A.
Carullo
, “
Four-day-follow-up study on the voice monitoring of primary school teachers: Relationships with conversational task and classroom acoustics
,”
J. Acoust. Soc. Am.
141
(
1
),
441
452
(
2017
).
17.
A.
Castellana
,
A.
Carullo
,
S.
Corbellini
, and
A.
Astolfi
, “
Discriminating pathological voice from healthy voice using cepstral peak prominence smoothed distribution in sustained vowel
,”
IEEE Trans. Instrum. Meas.
67
(
3
),
646
649
(
2018
).
18.
A.
Carullo
,
A.
Vallan
,
A.
Astolfi
,
L.
Pavese
, and
G. E.
Puglisi
, “
Validation of calibration procedures and uncertainty estimation of contact-microphone based vocal analyzers
,”
Measurement
74
,
130
142
(
2015
).
19.
G. E.
Puglisi
,
L. C.
Cantor Cutiva
,
L.
Pavese
,
A.
Castellana
,
M.
Bona
,
S.
Fasolis
,
V.
Lorenzatti
,
A.
Carullo
,
A.
Burdorf
,
F.
Bronuzzi
, and
A.
Astolfi
, “
Acoustic comfort in high-school classrooms for students and teachers
,”
Energy Procedia
78
,
3096
3101
(
2015
).
20.
P.
Bottalico
,
S.
Murgia
,
G. E.
Puglisi
,
A.
Astolfi
, and
K.
Ishikawa
, “
Intelligibility of dysphonic speech in auralized classrooms
,”
J. Acoust. Soc. Am.
150
(
4
),
2912
2920
(
2021
).
21.
A.
Astolfi
and
F.
Pellerey
, “
Subjective and objective assessment of acoustical and overall environmental quality in secondary school classrooms
,”
J. Acoust. Soc. Am.
123
(
1
),
163
173
(
2008
).
22.
F.
Minichilli
,
F.
Gorini
,
E.
Ascari
,
F.
Bianchi
,
A.
Coi
,
L.
Fredianelli
,
G.
Licitra
,
F.
Manzoli
,
L.
Mezzasalma
, and
L.
Cori
, “
Annoyance judgment and measurements of environmental noise: A focus on Italian secondary schools
,”
Int. J. Environ. Res. Public Health
15
(
208
),
208
(
2018
).
23.
I.
Polewczyk
and
M.
Jarosz
, “
Teachers' and students' assessment of the influence of school rooms acoustic treatment on their performance and wellbeing
,”
Arch. Acoust.
45
(
3
),
401
417
(
2020
).
24.
M.
Klatte
,
J.
Hellbrück
,
J.
Seidel
, and
P.
Leistner
, “
Effects of classroom acoustics on performance and well-being in elementary school children: A field study
,”
Environ. Behav.
42
,
659
692
(
2010
).
25.
M.
Picard
and
J. S.
Bradley
, “
Revisiting speech interference in classrooms
,”
Int. J. Audiol.
40
(
5
),
221
244
(
2001
).
26.
G.
Minelli
,
G. E.
Puglisi
, and
A.
Astolfi
, “
Acoustical parameters for learning in classroom: A review
,”
Build. Environ.
208
,
108582
(
2022
).
27.
W.
Yang
and
J. S.
Bradley
, “
Effects of room acoustics on the intelligibility of speech in classrooms for young children
,”
J. Acoust. Soc. Am.
125
(
2
),
922
932
(
2009
).
28.
M.
Hodgson
and
E. M.
Nosal
, “
Effect of noise and occupancy on optimal reverberation times for speech intelligibility in classrooms
,”
J. Acoust. Soc. Am.
111
(
2
),
931
939
(
2002
).
29.
P.
Bottalico
and
A.
Astolfi
, “
Investigations into vocal doses and parameters pertaining to primary school teachers in classrooms
,”
J. Acoust. Soc. Am.
131
(
4
),
2817
2827
(
2012
).
30.
D.
Pelegrín-García
,
J.
Brunskog
, and
B.
Rasmussen
, “
Speaker-oriented classroom acoustics design guidelines in the context of current regulations in European countries
,”
Acta Acust. united Acust.
100
,
1073
1089
(
2014
).
31.
G.
Calosso
,
G. E.
Puglisi
,
A.
Astolfi
,
A.
Castellana
,
A.
Carullo
, and
F.
Pellerey
, “
A one-school year longitudinal study of secondary school teachers' voice parameters and the influence of classroom acoustics
,”
J. Acoust. Soc. Am.
142
(
2
),
1055
1066
(
2017
).
32.
K.
Mealings
, “
Classroom acoustic conditions: Understanding what is suitable through a review of national and international standards, recommendations, and live classroom measurements
,” in
Proceedings of ACOUSTICS 2016
,
Brisbane, Australia
(November 9–11,
2016
).
33.
National Acoustic Laboratories
(
2016
). “
Classroom acoustic conditions: Understanding what is suitable through a review of national and international standards, recommendations, and live classroom measurements
,” https://dspace.nal.gov.au/xmlui/handle/123456789/521 (Last viewed December 2021).
34.
ANSI/ASA 12.60
,
Acoustical Performance Criteria, Design Requirements, and Guidelines for Schools: Part 1. Permanent Schools
(
Acoustical Society of America
,
New York
,
2010
).
35.
Classroom Acoustics I: A Resource for Creating Learning Environments with Desirable Listening Conditions
(
Acoustical Society of America
,
Melville, NY
,
2003
).
36.
Classroom Acoustics for Architects: A Companion Booklet for ANSI/ASA S12.60 Parts 1 and 2
(
Acoustical Society of America
,
Melville, NY
).
37.
Education Funding Agency
,
Acoustic Design of Schools: Performance Standards
, Building Bulletin 93 (
Department for Education
,
London
,
2015
).
38.
UNI 11532-2
,
Caratteristiche acustiche interne di ambienti confinati—Metodi di progettazione e tecniche di valutazione—Parte 2: Settore scolastico (Acoustic characteristics of indoor environments—Design methods and evaluation techniques—Part 2: school sector)
(
Ente Italiano di Normazione
,
Milan, Italy
,
2020
).
39.
DIN 18041, 2004-05
,
Hörsamkeit in Kleinen Bis Mittelgroßen Räumen (Acoustical Quality in Small to Medium-Sized Rooms)
(
Deutsche Institut für Normung
,
Berlin
,
2016
).
40.
E.
Greenland
and
B.
Shield
, “
Towards accessible acoustic criteria for inclusion in mainstream classrooms
,” in
Proceedings of the 23rd International Congress on Acoustics
,
Aachen, Germany
(September 9–13,
2019
).
41.
P.
Bottalico
,
S.
Murgia
,
G. E.
Puglisi
,
A.
Astolfi
, and
K. I.
Kirk
, “
Effect of masks on speech intelligibility in auralized classrooms
,”
J. Acoust. Soc. Am.
148
,
2878
2884
(
2020
).
42.
B.
Shield
and
J. E.
Dockrell
, “
The effects of environmental and classroom noise on the academic attainments of primary school children
,”
J. Acoust. Soc. Am.
123
,
133
144
(
2008
).
43.
B.
Shield
and
J. E.
Dockrell
, “
External and internal noise surveys of London primary schools
,”
J. Acoust. Soc. Am.
115
(
2
),
730
738
(
2004
).
44.
J. S.
Bradley
, “
Speech intelligibility studies in classrooms
,”
J. Acoust. Soc. Am.
80
(
3
),
846
854
(
1986
).
45.
J. S.
Bradley
, “
Review of objective room acoustics measures and future needs
,”
Appl. Acoust.
72
,
713
720
(
2011
).
46.
J. S.
Bradley
,
R. D.
Reich
, and
S. G.
Norcross
, “
On the combined effects of signal-to-noise ratio and room acoustics on speech intelligibility
,”
J. Acoust. Soc. Am.
106
(
4
),
1820
1828
(
1999
).
47.
H.
Sato
and
J. S.
Bradley
, “
Evaluation of acoustical conditions for speech communication in active elementary school classrooms
,”
J. Acoust. Soc. Am.
123
,
2064
2077
(
2008
).
48.
D.
Pelegrín-García
,
J.
Brunskog
,
V.
Lyberg- Åhlander
, and
A.
Löfqvist
, “
Measurement and prediction of voice support and room gain in school classrooms
,”
J. Acoust. Soc. Am.
131
(
1
),
194
204
(
2012
).
49.
EN ISO 3382-2
, “Acoustics–Measurement of room acoustic parameters–Part 2: Reverberation time in ordinary rooms” (
International Organization for Standardization
,
Geneva, Switzerland
,
2009
).
50.
UK Department of Transport
, “Guidance on road classification and the primary route network,” https://www.gov.uk/government/publications/guidance-on-road-classification-and-the-primary-route-network/guidance-on-road-classification-and-the-primary-route-network#introduction (Last viewed August 7, 2022).
51.
NTi Audio
, “
NTi Audio TalkBox operating manual
,” https://www.nti-audio.com/Portals/0/data/en/TalkBox-Manual.pdf (Last viewed December 12, 2021).
52.
IEC 60268-16
,
Sound System Equipment. Part 16: Objective Rating of Speech Intelligibility by Speech Transmission Index
(
International Electrotechnical Commission
,
Geneva, Switzerland
,
2011
).
53.
W. T.
Chu
and
A. C. C.
Warnock
, “
Detailed directivity of sound fields around human talkers
,”
Research Report RR104
(
National Research Council Canada
,
Ottawa, Canada
,
2002
).
54.
H. J. M.
Steeneken
and
T.
Houtgast
, “
Mutual dependence of the octave-band weights in predicting speech intelligibility
,”
Speech Commun.
28
(
2
),
109
123
(
1999
).
55.
N. M.
Papadakis
and
G. E.
Stavroulakis
, “
Review of acoustic sources alternatives to a dodecahedron speaker
,”
Appl. Sci.
9
,
3705
(
2019
).
56.
A.
Astolfi
,
V.
Corrado
, and
A.
Griginis
, “
Comparison between measured and calculated parameters for the acoustical characterization of small classrooms
,”
Appl. Acoust.
69
,
966
976
(
2008
).
57.
G. E.
Puglisi
,
A.
Astolfi
,
L. C.
Cantor Cutiva
, and
A.
Carullo
, “
Assessment of indoor ambient noise level in school classrooms
,”
Proceedings of the Conference on Noise Control—EuroNoise2015
,
Maastricht, Netherlands
(May 31–June 3,
2015
).
58.
EN ISO 3382-1
, “Acoustics–Measurement of room acoustic parameters–Part 1: Performance spaces” (
International Organization for Standardization
,
Geneva, Switzerland
,
2009
).
59.
M. R.
Hodgson
, “
Rating, ranking, and understanding acoustical quality in university classrooms
,”
J. Acoust. Soc. Am.
112
(
2
),
568
575
(
2002
).
60.
C.
Croux
and
C.
Dehon
, “
Influence functions of the Spearman and Kendall correlation measures
,”
J. Ital. Stat. Soc.
19
,
497
515
(
2010
).
61.
K.
Hajian-Tilaki
, “
The choice of methods in determining the optimal cut-off value for quantitative diagnostic test evaluation
,”
Stat. Methods Med. Res.
27
(
8
),
2374
2383
(
2018
).
62.
H. K.
Zou
,
A. J.
O'Malley
, and
L.
Mauri
, “
Receiver-operating characteristic analysis for evaluating diagnostic tests and predictive models
,”
Circulation
115
(
5
),
654
657
(
2007
).
63.
S.
Secchi
,
A.
Astolfi
,
G.
Calosso
,
D.
Casini
,
G.
Cellai
,
F.
Scamoni
,
C.
Scrosati
, and
L.
Shtrepi
, “
Effect of outdoor noise and facade sound insulation on indoor acoustic environment of Italian schools
,”
Appl. Acoust.
126
,
120
130
(
2017
).
64.
H.
Kuttruff
,
Room Acoustics
(
Spon
,
London
,
2009
).
65.
T.
Houtgast
,
H.
Steeneken
, and
R.
Plomp
, “
Predicting speech intelligibility in rooms from the modulation transfer function. I. General room acoustics
,”
Acta Acust. united Acust.
46
(
1
),
60
72
(
1980
), available at https://www.ingentaconnect.com/content/dav/aaua/1980/00000046/00000001/art00010.
66.
See supplementary material at https://www.scitation.org/doi/suppl/10.1121/10.0013504 for boxplots of each parameter for the groups of compliant (C) and non-compliant (NC) classrooms based on the groupings (a) and (b).
67.
S. G. R.
Prakash
,
R.
Rangasayee
, and
P.
Jeethendra
, “
Low-cost assistive noise level indicator for facilitating the learning environment of school going children with hearing disability in inclusive educational setup
,”
Ind. J. Sci. Technol.
4
(
11
),
1495
1504
(
2011
).
68.
J.
Van Tonder
,
N.
Woite
,
S.
Strydom
,
F.
Mahomed
, and
D. W.
Swanepoel
, “
Effect of visual feedback on classroom noise levels
,”
S. Afr. J. Child. Educ.
5
(
3
),
a265
(
2016
).
69.
S. D.
Blasio
,
G.
Vannelli
,
L.
Shtrepi
,
G. E.
Puglisi
,
G.
Calosso
,
G.
Minelli
,
S.
Murgia
,
A.
Astolfi
, and
S.
Corbellini
, “
Long-term monitoring campaigns in primary school: The effects of noise monitoring systems with lighting feedback on noise levels generated by pupils in classrooms
,” in
Proceedings of the 48th International Congress and Exhibition on Noise Control Engineering—Inter-Noise 2019
,
Madrid, Spain
(June 16–19,
2019
).
70.
J. S.
Bradley
,
H.
Sato
, and
M.
Picard
, “
On the importance of early reflections for speech in rooms
,”
J. Acoust. Soc. Am.
113
,
3233
3244
(
2003
).
71.
C.
Visentin
,
M.
Pellegatti
, and
N.
Prodi
, “
Effect of a single lateral diffuse reflection on spatial percepts and speech intelligibility
,”
J. Acoust. Soc. Am.
148
(
1
),
122
140
(
2020
).
72.
S. D.
Blasio
,
G. E.
Puglisi
,
C.
Gervasi
,
A.
Castellana
,
S.
Murgia
,
G.
Minelli
,
G.
Vannelli
,
S.
Corbellini
,
A.
Carullo
, and
A.
Astolfi
, “
A pilot study in primary school on the effect of noise monitoring system with lighting feedback on teachers' voice parameter, noise levels and subjective assessments
,” in
Proceedings of the 23rd International Congress on Acoustics
,
Aachen, Germany
(September 9–13,
2019
).
73.
E.
Arvidsson
,
E.
Nilsson
,
D.
Bard-Hagberg
, and
O. J. I.
Karlsson
, “
Subjective experience of speech depending on the acoustic treatment in an ordinary room
,”
Int. J. Environ. Res. Public Health
18
,
12274
(
2021
).
74.
E.
Arvidsson
,
E.
Nilsson
,
D.
Bard-Hagberg
, and
O. J. I.
Karlsson
, “
Difference in subjective experience related to acoustic treatments in an ordinary public room: A case study
,”
Acoustics
3
,
442
461
(
2021
).

Supplementary Material

You do not currently have access to this content.