PROCEEDINGS of the
23rd International Congress on Acoustics
9 to 13 September 2019 in Aachen, Germany

Improvement of the sound environment for supporting
communication at nursery facilities: Approaches for changing room
acoustics and users’ minds
Saki NOGUCHI1; Kanako UENO2
1,2

Meiji University, Japan

ABSTRACT
Nursery facilities in Japan have recently been experiencing problems with their sound environments, suchas insufficient sound absorption and high volume of generated sound. We therefore examined someapproaches to creating an acoustic environment that supports communication in the classroom. As a resultof addressing room acoustics by installing materials with an average sound absorption coefficient of 0.25 ormore in the classroom, both the impression of the sound and the teacher’s reported ease in listening tochildren’s voices when many sounds were generated was improved. To address users’ minds, we conducteda workshop for 5- to 6-year-old children and their nursery teachers to make them conscious of the dailysound environment and to instruct them in how to identify pleasant sounds and to allow them to experience
the corners of the room, treated with sound absorption materials. As a result, the children and preschool
teachers came to understand that unnecessarily loud speech led to environmental noise, and that they could
relax and enjoy sounds in spaces surrounded by sound absorption materials.
Keywords: Acoustic environment, Preschool facility, Sound absorption, Workshop for children

1. INTRODUCTION
In early childhood, when mental and physical development is critical, creating the rightenvironment for supporting smooth communication is an important consideration. In Japan, acoustic
environmental issues such as noise or persistent reverberations exist in early childhood education
facilities (1). These are some of the factors that disrupt communication between children andpreschool teachers. It has been reported that the installation of sound absorption materials inclassrooms is an effective method to mitigate noise (2) and improve speech intelligibility (3).
We have previously reported on the influence of sound absorption conditions on childcare
activities (4). In this paper, we consider the acoustic environment and its influence oncommunication between children and preschool teachers.
Based on this, we present a practical approach for changing room acoustics and users’ minds toimprove the sound environment in order to support communication at nursery facilities. We
investigated the impact of these approaches on communication and educational activity from various
perspectives.

2. METHODOLOGY
Our research was conducted at two nursery facilities where the teachers have had conscious ofproblems with the sound environment. The facility outlines are presented in Tab.1.
At S Kindergarten, our approach addressed room acoustics. Rock wool sound absorption board
was already installed on the ceilings of the classrooms. However, one classroom used to teach4-year-olds was a converted warehouse and no sound absorption materials had been installed. The
1
2

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n-saki@akane.waseda.jp
uenok@meiji.ac.jp

class teacher was concerned about sound reverberation, and so this class was targeted.
At U nursery school, our approach involved addressing users’ minds. At this facility, large rooms
were used for a variety of age groups. The corners of the rooms are set up for different activities.
Although the sound absorption efficiency of the rooms was high, the teachers had a problem in termsof overall noise levels when all 80 children (including 3-, 4-, and 5-year-olds) were active. Therefore,
in order to think a comfortable sound environment with the children and to address the problems
described by the teachers, we made the corners of this room and ran a workshop for children.
Table 1 – Outline of the facilities
Backgroundinformation

Architecture

Number ofoccupants

S kindergarten
U nursery school
School corporation, established in 1956, Kanagawa
Social welfare corporation, established in
prefecture
1954, Saitama prefecture
Built in 1978, repaired in 2013
Built in 2011
Structure: Reinforced concrete
Structure: Reinforced concrete
Location: Residential area, adjacent to university and temple
Location: Residential areas, adjacent to temple[Classroom] Floor space: 51.6 m², Ceiling height: 2.4 m,[Classroom] Floor space: 215 m²,
Ceiling finish material: Rock wool sound absorption board
Ceiling height: 2.4 m, Ceiling finish material:(Except for target room A which contained a decorated
Perforated gypsum board
plaster board ceiling)
Staff (preschool teachers): 25 (14)Staff (preschool teachers): 33 (24)Children (3, 4, 5 years old): 288
Children (0-5 years old): 150
Each one of the three grade 3 classes
Multi-age class (0, 1 / 2 / 3, 4, 5 years old)

3. AN APPROACH TO CHANGING ROOM ACOUSTICS: A FIELD EXPERIMENTINVOLVING THE INSTALLATION OF SOUND ABSORPTION MATERIALS
3.1

Experimental methodology

Blackboard

Locker
5400 mm

	
 
	
 
	
 
	
 
	
 
	
 
	
 
	
 

Door

3.1.1 Experiment procedure
An outline of the target room is shown in Fig.1. In this experiment, in order to find the mosteffective sound absorption conditions for the classroom, we set up four different arrangements. The
experiment schedule is shown in Tab.2, the experimental conditions are shown in Tab.3, and aphotograph of the installation is shown in Fig.2.

Corridor
Recording Point
9000 mm(a) Floor plan

Ceiling height=2400 mm(b) Original state of the classroom
Figure 1 – Outline of classroom A
Table 2 – Experiment schedule

Schedule
Condition
Oct. 17th, 2017 – Oct. 31th	
  	
  	
  A
	
 
Nov. 6th – Nov. 17th

B

Nov. 20th – Dec. 1stC

Dec. 4th – Dec. 14th
Jan. 15th, 2018 – Jan.19th
Jan. 22th – Feb. 2ndA
DSurvey[1] Survey for condition A1 (prior to installation -1)
Installation of sound absorption materials[2] Survey for condition B
Removal of some of the sound absorption materials[3] Survey for condition C
Removal of all the sound absorption materials[4] Survey for condition A2 (after removal)[5] Survey forcondition
A3 (prior
to installation -2)
Installationof soundabsorption
materials[6] Survey for condition D

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Table 3 – Experimental conditions
Condition
Installation area (Ceiling) [m2]Installation area ratio
Number of POLYWOOL® pieces installedA(170*400*50 mm, Fukoku Co., Ltd., a porous
sound absorption materials made of polyester)

Reverberation time (1 kHz) [s]Avg. sound absorption coefficient (1 kHz)

0.77
0.14

B
22.8
44.3%

C
3.1
5.9%

D
7.5
14.5%

336

45

110

0.36
0.30

0.54
0.20

0.44
0.25

Figure 2 – Condition D installation
	 Condition A (average sound absorption coefficient α = 0.14) did not involve the installation ofsound absorption materials, condition B ( α = 0.3) involved the installation of the maximum possibleamount of sound absorption material, condition C ( α = 0.2) involved an installation that was
equivalent to the recommended values for school classrooms, and condition D ( α = 0.25) was
midway between conditions B and C. In order to facilitate the preschool teacher’s evaluation of theinstallation’s suitability for educational activities, we changed the installation to match the Japanese
recommended values for school classrooms after first presenting conditions that made it easy todetect changes in the acoustic environment.	
 3.1.2 Survey method
To verify the effectiveness of the sound absorption material installation, an acoustic environment
survey, an observational survey, and an interview with the preschool teacher were conducted.
The acoustic environment survey involved capturing the characteristics of the acoustic
environment by listening to and analyzing the generated sound. The sound was recorded using asound level meter microphone (RION NL-42) and a recorder (OLYMPUS DS-901). In theobservational survey, observational records and video data were acquired. The characteristics wereorganized according to the particulars of the acoustic environment, the state of communication
between the children and the preschool teacher. The interview was conducted with the preschool
teacher in room A (T(a)). During the experiment, we asked her about her impression of the acoustic
environment and its influence on the activities performed in the class.
3.2

Results

LAeq,1min [dB]3.2.1 Effects of installation changes on the acoustic environment
In this section, the improvements in the acoustic environment were extracted from reference (4)and outlined. The typical daily sound levels (L Aeq, 1min ) prior to the experiment are shown in Fig. 2
along with some photographs of the types of activities taking place at each station as shown in Fig. 3.
Free play Class activity
90
85
80
75
70
65
60
55
10:00
11:00

Lunch à Free play

12:00

Class gathering, Reading picture book

13:00

14:00

Figure 2 – Changes in sound pressure levels (LAeq, 1min) and type of associated activity occurring in room A(a) Lunchtime(b) Free play
Figure 3 – Types of activities

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Proportion [%]Proportion [%]In free times, such as play and lunch, sound was generated simultaneously and frequently, and thelevel was as high as 80-85 dB. At the storytelling situation, the sound levels were less than 70 dB,
creating an environment where the children could listen quietly.
Based on these characteristics, in order to analyze the noise mitigation effect of the installedsound absorption materials, we analyzed the lunchtime and free play times after lunch. Fig. 4 shows
the frequency distribution for L Aeq, 1min under each condition (A: [1] prior to installation -1).
	
 
50
50
[1] A (α!=0.14)	  [1] A (α!=0.14)[2] B (α!=0.3)[2] B (α!=0.3)40	 40[3] C (α!=0.2)[3] C (α!=0.2)30	 30[6] D (α!=0.25)[6] D (α!=0.25)
	
 
20
20
	
 
10	
 
10
	
 
0
0
66- 68- 70- 72- 74- 76- 78- 80- 82- 84- 86	  66- 68- 70- 72- 74- 76- 78- 80- 82- 84- 86[dB][dB](a) Free play	  (b) Lunchtime
Figure 4 – Frequency distribution for the A-weighted sound pressure levels (LAeq, 1min)
In both activities, it could be confirmed that for [2] B and [6] D, the distribution of low soundpressure levels was large as the sound absorption efficiency was high, and in [1] A and [3] C, thedistribution at high sound pressure levels was large. It could be concluded that the sound absorption
efficiency effectively reduced the noise levels for an average sound absorption coefficient of 0.25 orgreater when sounds were simultaneously and frequently produced.
3.2.2 Influence on communication
In this section, we will discuss the acoustic environment’s influence on communication in termsof the results of the interviews (4) and the observational surveys. In the interview, we asked about
the teacher’s impressions of the acoustic environment, the behavior of the children, and the acoustic
environment’s influence on the teacher’s educational activities. The interview results regarding theinfluence on communication are listed in Tab.4.
Table 4 – Results from the interviews with preschool teachers
Condition[1]○, [4]●A (𝛼=0.14)[2] B (𝛼=0.3)[3] C (𝛼=0.2)[6] D (𝛼=0.25)

Influence on communication〇T(a) experienced discomfort within the acoustic environment but did not experience any particular
influence on her educational activities.
●The children’s speech became louder so as to be heard over the background noise.
●T(a) could not discern the children’s voices at play time, although she was aware that they werespeaking.
●T(a) was less able to use sound levels than when she was exposed to condition C.
●The number of times the piano was used to signal clearing up increased compared to condition C.
•T(a) became able to discern the children’s voices during free play.
•T(a) became able to add sound intonation. (Use of the piano, voices intonation during storytelling, etc.)•It was easy for children to sing and they could sing with meaningful lyrics.
•At play time, an activity was held during which the children enjoyed conversations, such as talking
secretly or speaking to people at a distance.
•The children were able to listen to T(a)'s voice and were able to understand it well.
•Children's voice grew louder.
•The children’s voices became difficult to hear.
•T(a) led the children playing with the instrument to another play.
•T(a) tried to suppress the intonation of the sound because of the excess reverberation.
•The number of times the piano was used to signal clearing up increased.
•T(a) had to alert the children about the loudness of their voices more often•At play time, T(a) felt that the children were interested in another play in a different place.
•At play time, T(a) could more easily pay attention their play in remote areas and react to them.
•T(a) felt that the ease of storytelling and music activities was identical to Condition B.
•The children and T(a) were able to enjoy the sound of playing.

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In the interview, T(a) indicated that the sound levels caused hearing discomfort and were noisy
under conditions A and C. However, under conditions B and D, the hearing discomfort waseliminated, and the sound could be clearly discerned and their impression of the acoustic
environment improved. These points were identical for the observer. Under the conditions A and C,
the high-pitched sounds made by children playing with toys were amplified, and the voices ofchildren also appeared to grow louder. Hearing discomfort was experienced under suchcircumstances and it was difficult for the participants to talk. We could not hear children speaking inclose proximity to us when at play, and we had to rely on visual information to decode their behavior.
On the other hand, in conditions B and D, there was no associated hearing discomfort and it was anenvironment in which we could listen to sounds and voices even at a distance.
The influence on communication was mentioned in terms of its effects on vocalization, listening,
behavior, and educational activities. Under conditions A and C, the children's voices tended to be
loud, and the teacher used a method to draw their attention that did not rely on raising her voice, suchas using the piano to create a signal tone. At the free play, the teacher could not hear the children’s
voices and speech intelligibility was thus poor. On the other hand, in conditions B and D, both thechildren and the teacher were able to listen to each other's voices, and communication appeared to besmooth. It was proposed that this was because the speech transmission performance was improved by
the reduction of the noise levels and the improvement of the sound absorption efficiency. In addition,
it was mentioned that it became possible to communicate for enjoyment of the sound, such as
engaging in sound play, storytelling, and music activities. Tab. 5 described a specific case example
that was indicative of the acoustic environment’s influence on educational behavior.
Table 5 – Specific case example of educational behavior at the play station under condition D
An example of a popular play amongst the children was sending letters. One child (C(a)) drew a picture on a piece of paperand handed it to another child (C(b)), but C(b) would not receive it because C(b) did not understand that it was a letter. WhenT(a) was interacting with another child at a distance, she heard the dialogue. Therefore, T(a) prepared some pieces of papers
by drawing a picture of an envelope on it in support of the letter play. According to T(a), she had always wanted to hear thechildren’s voices but she had not been able to listen to any voices other than the children she was directly speaking with.

In this case, the improvement of the acoustic environment led to educational action in terms of the
proposal of new material for play. In other words, the speech intelligibility improvement made it
possible to pay attention to each conversation and grasp the content of multiple, simultaneousconversations. Thereby, it became possible for the teacher to intervene in communication between
the children as required. Since preschool teachers always act on a holistic understanding of thesituation, environments where the voice can be heard support the behavior of the preschool teacher interms of listening to the voices of children and assisting them. The outcome of such activities is an
improvement in the communication between the children and the preschool teacher, considered to beof great educational importance. In addition, in a better acoustic environment, it was also found thatthe teacher could determine own behavior such as returning words or watching over, and the children
would thus play more calmly as a result of the teacher’s change. It was suggested that the
improvement of the acoustic environment would support the preschool teachers as they make such
immediate situational judgments.

4. USERS’ MINDS APPROACH: SOUND ENVIRONMENT WORKSHOP FOR
CHILDREN
4.1

Outline4.1.1 Pre-workshop trial
Prior to the workshop (WS), we prepared the corners of the room suitably for the planned
activities in terms of the acoustic environment. Specifically, sound absorption materials were
installed to create quiet places in a large, lively room. The schedule of activities is shown in Tab.6,
and the corner installations are described in Fig.5. Two types of sound absorption materials(POLYWOOL®: 50mm, a porous sound absorption materials made of polyester, Fukoku Co., Ltd.
and TAFNEL ™ : a long fiber nonwoven fabric, Mitsui Chemicals Inc.) were used. The corner
installations were completed by installing the sound absorption materials in the corner or creating aspace surrounded by sound absorption materials (such as the small space (5)). In each phase,4126

interviews were conducted with 3 teachers (the director, the chief teacher, and the teacher assigned to
the 5-year-olds’ class) for evaluation, and the results were fed back to this trial.
Table 6 – Schedule of trial
Schedule
TrialMar., 2018	
  First	  	  visit,	  measurement of reverberation time and sound pressure levels
Apr. – Oct. Site meeting and making corner.
Oct. 31th Reflection of making a corner, WS meeting
Nov. WS planning and preparation
Nov. 21th 1st WS
Nov. 27th 2nd WS
Dec. 10th Interview after WS
Dec. – Feb., 2019 WS follow up
Block

Side: POLYWOOL,
Front: TAFNEL

Gathering,
Lunch
Den

17400mm	 	
 free space

Picture book

Side: POLYWOOL,
Front: TAFNEL

Relax
Drawing,
Producing

15400mFree

Setting corer

m plan(a) Floor

W:0.5m D:0.7m
H:0.8m(b) Relaxation corner:

	
 
	
 
	
 
	
 
	
 
	
 
W:1.5m D:1.2m H:1.3m
	 (c) Free corner:

Small space for an individual child

TAFNELPOLYWOOL(d) Picture book corner:
Small space for multiple children

Figure 5 – Corner arrangements
The relaxation corner and the picture book corner were noted as appearing to induce a sense ofcalm because of the surrounding sound absorption materials, and were used willingly. On the other
hand, the purpose of the small space for some children was unclear (Fig. 5 (c)), so it was necessary to
discuss its use. After assessing the corners, the staff pointed out the need to consider how to control
the liveliness of the children's voices and how to use the corners in interacting with the children.
Therefore, a WS was organized as an opportunity to consider the enhancement of the level ofcomfort of the sound environment.
4.1.2 Outline of the WS
We ran the WS to encourage children and teachers to review their daily environment along with
their actions and their indoor spaces, focusing on the sound environment. The program on the day of
the WS is shown in Tab.7.
Table 7 – WS program: “Let’s think about comfortable sounds!”[1st WS] Aim: Pay attention to the sound environment. Know thedifferences in how they experience sound with others.

[2nd WS] Aim: Experience the 3 corners and explore
how to remain there and enjoy the sounds

1) Greeting, Introduction (10min.)1) Greeting, Introduction (10min.)2) Experience: Overall activity (40min.)
X: Listening to the sound (Sound quizzes, talking about their mostand least favorite sounds)
Y: Think about noise pollution (After listening to the recorded
lunchtime sounds, responding to the sound by raising their hand
if they think it's unpleasant to hear the sound volume rising)
Z: Think about how to act in response (Try to act with pleasantsounds using VoiceScale (6))2) Experience: Group activity (40min.)x: Relaxation corner (Enter the small space alone andplay the sound of a pleasant musical instrument)y: Sound laboratory (Learn how to make sounds withmusical instruments, discover pleasant sounds)
z: Picture book corner (Listen to picture books, enjoy
reading aloud paying attention to the volume of thevoice.)

3) Conclusion (10min.)3) Conclusion (10min.)

The WS was conducted twice (Nov. 21th, 27th) in the morning on typical days. The participants
included 26 5-year-old children, 3 teachers, and 5-6 WS staff. The first WS was an opportunity to
discuss comfortable sounds while sharing in the experience of listening to and producing sounds with4127

all participants. At the second WS, the participants were divided into three groups and experienced
three corners at which they could relax, enjoy sounds, and enjoy picture books. Then they considered
how to remain there. The WS staff asked the children how to remain comfortable, and tried to
explore the pleasant sound environment with the children. After the WS, we conducted aquestionnaire and interviewed the 3 teachers, asking them to evaluate the WS and the changes in thechildren and preschool teachers subsequent to the WS.
4.2 Result
Based on the experiences at the WS and the results of teacher surveys, we could evaluate the WS.
Some scenes from the WS are shown in Fig.6 and 7, and the WS activities are described in Tab.8.

ΩΩΩ(a) Y: “Raise your hand if you think it’s noisy” (b) Z: “Let's stack dishes making a pleasant sound”
Figure 6 – Activity situations from the 1st WS

	
 
	
 
	
 
(a) x: Relaxation corner(b) y: Sound laboratory(c) z: Picture book corner
Figure 7 – Activity situations from the 2nd WS
Table 7 – Situation of WS activities･Many children answered quiz questions and shared their feeling of least favorite and most favorite sounds.
･The consensus was that there was a variety of feelings associated with sounds.
･The children listened to the typical, recorded lunch time sounds and concluded that loud voices cause noisy.
Y･It was difficult to experience the loudness because the recorded sound and the voices emitted during the WS overlapped.
1st･Both children who were taking part in the activity and those who were watching focused on being quiet while
becoming aware that the display changed in accordance with the sound volume.
Z･Some statements from the children included: "I thought it was good because they were kind voices", and: "I thought
it would be good to treat dishes carefully".
･The children entered the small space alone and had to work out how to play a pleasant sound and listened to it attentively.
x ･The preschool teacher told to the children that the sound generated by them was gentle and felt that it was anopportunity to spend time alone and to explore the pleasant sound.
2nd ･Proposing a method of using sound that was different from the usual practice promoted exploration in order to findypleasant sounds.
･It was commonly understood as a place to calmly read picture books and to enjoy reading aloud.
z･The children appeared to concentrate on the picture books while relaxing.
X

In the 1st WS, “listening to the sound” was the common activity, and children and teachers
discussed their favorite sounds, comfortable sounds and noisy sounds together. For children,
listening to the sound of their daily activities and watching other children doing the activities seemed
to be an opportunity to consider and reflect on their own behavior patterns. In the 2nd WS, the corner
experiences helped participants to think about how to remain from the point of sound (x, z) and toenjoy listening to and generating sound (y, z). It seemed that it was appreciated as an opportunity forchildren to reflect on how to use the corner and to explore how to enjoy playing with sound. It also
seemed that the preschool teachers benefitted by gaining a new point of view from their experiences4128

in the corners in terms of experiencing speech methods and sound enjoyment, and the effects ofsound absorption materials. The teachers indicated that they were satisfied as a whole.
In the interview after the WS, the teacher indicated that the children had begun thinking aboutpleasant sounds and acting on these thoughts, leading to behavior such as advising the teacher not to
use a loud voice or devising and playing instruments during music activity times. In addition, it
seemed that the teachers also considered their response and were eager to use sound as a basis for
future educational activities. In addition, the three proposed corners became quite popular, andteachers indicated that they would like to continue using them. In addition, one of the responses wasthat "by listening to the sounds that the children liked, we were able to deepen our understanding of
how the children were experiencing their daily activities". This was considered a possible method ofleading the children in their growing understanding through the use of sound.
From this exercise, the children and preschool teachers understood that unnecessarily loud speech
led to noise, and that they could relax and enjoy sounds in the spaces surrounded by sound absorption
materials. The activities presented in the sound experience WS were an opportunity for users toreflect on their daily sounds, become aware of pleasant sounds for themselves and others, and to
consider creating a pleasant sound environment. In other words, the approach involving users’ minds
was thought to have led to improvements in their communication.

5. CONCLUSIONSThis study’s aim was to improve the sound environment to support child–teacher communicationin nursery facilities. We approached this in terms of both room acoustics and users’ minds, andexamined how they both affected communication. In terms of room acoustics, it was proposed thatthe improvement of the sound absorption efficiency made it possible to improve the quality of theircommunication in situations where sounds were emitted simultaneously, enhancing the educational
behavior. In terms of users’ minds, through mutual experience of the sound environment, thechildren and preschool teachers came to understand that unnecessarily loud speech led to noise, andthat they could relax and enjoy sounds in the spaces surrounded by sound absorption materials. It
was proposed that an improvement in awareness of the sound environment changed user personal
behavior patterns and introduced the preschool teachers to new perspectives on education in terms ofthe creation of environments and associated educational activities.
It was thus suggested that the sound environment exerted diverse influences on preschool
activities, and improvement of the acoustic environment enabled superior communication.

ACKNOWLEDGEMENTS
We would like to thank the teachers of the Sansho kindergarten and Urawa Hinadori nurseryschool for their cooperation in this study. We are grateful to Prof. Arata Yoshida and Assoc. Prof.
Tomoko Katakawa for their helpful discussions concerning early childhood education. This study
was supported by JSPS KAKENHI Grant Number JP16H03274, JP18K13127.

REFERENCES
1. K. Kawai, K. Ueno, S. Takeoka & H. Funaba. Overview of acoustic environment of nursery facilities inJapan – Present situation and recent studies. Proceedings of 7th Forum Acusticum 2014 (FA 2014),
R03C_7, Krakow, 2014.
2. K. Miyatsuka, S. Takeoka & K. Ueno. The field experiment on the installation method ofsound-absorbing material in a nursery space. Summaries of technical papers of annual meeting 2015, pp.
277-278, 2015. (in Japanese).
3. K. Kawai & S. Fujihara. Mitigation of noise in nursery classrooms by sound absorption, Part 3: A casestudy on acoustically renovated classrooms. INTER-NOISE 2013, Vol.5, pp.4964-4968, Innsbruck
AUS, 2013.
4. S. Noguchi & K. Ueno. A field experiment on proper condition of sound absorption in kindergarten
classroom. AIJ Journal of Technology and Design, Vol. 25, No.60, 725-729, 2019. (in Japanese).
5. K. Ueno, S. Watanabe & S. Noguchi. A field study on the acoustic environment of special needs
education classrooms. Proceedings of Euronoise 2018, pp.1801-1805, Crete, 2018.
6. K. Ueno & S. Ise. Visualization of voice levels for improving the sound environment in preschools.
Proceedings of Euronoise 2018, pp.1867-1870, Crete, 2018.

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