CAAM: A Novel Classroom Acoustics Assessment Model

for Enhancing Learning Quality (Case Study: KAU)

Amin Y. Noaman

, Abdul Hamid M. Ragab

, Ayman G. Fayoumi

Adman I. Madbouly

and Ahmed M. Khedra

Faculty of Computing and Information Technology, King Abdulaziz University,

Jeddah, Saudi Arabia

Deanship of Admission and Registration, King Abdulaziz University, Jeddah, Saudi Arabia

Abstract. In this paper, a new classroom acoustics assessment model (CAAM)

for enhancing speech intelligibility and learning quality is proposed. The model

is based on five main criteria that affect the learning process and related to

classrooms acoustical properties. These include classroom specifications, noise

sources inside and outside the classroom, teaching style, and vocal effort. The

priority and weights of these major criteria along with their alternatives are

identified using the views of students, staff, education consultants, and expertise

by using a developed questionnaire, and the AHP methodology. This Model

can be considered as a helpful framework enabling KAU decision makers to

take effective decisions on classroom acoustics treatment issues. It also pro-

vides KAU higher authorities the suitable guidelines that help for determine

necessary requirements that help to raise the quality and efficiency of the edu-

cational environment; in order to reach an excellent learning environment; and

hence increasing students learning outcomes.

1 Introduction

Education for all citizens is essential to all modern societies. Usually formal education

is conducted in classrooms, where the learning process involves intensive verbal

communication between students and teachers and among students. The quality and

efficiency of this kinds of communications, and hence, quality of learning and teach-

ing environment is measured by the acoustics conditions of the classrooms [1]. The

existence of high levels of noise in the classroom will affect the learning and teaching

environment for both students and teachers, and will make students tired prematurely,

and consume their cognitive abilities that can be used better employed in paying more

attention to and understanding the content of their classes [2].

Building classroom with good acoustics is one of the important design considera-

tions for new classrooms. Achieving this from the beginning is a straight forward

solution of the Acoustics problems that may be found inside classroom; however

existing classrooms acoustics treatment is the only way to overcome the existing

classrooms acoustics problems that affect the sound intelligibility inside classroom

and consequently affect the learning quality and learning outcomes. The aim of the

present research project is to develop a classroom acoustics treatment model that can

Y. Noaman A., Hamid M. Ragab A., G. Fayoumi A., I. Madbouly A. and M. Khedra A..

CAAM: A Novel Classroom Acoustics Assessment Model for Enhancing Learning Quality (Case Study: KAU).

DOI: 10.5220/0004535200030013

In Proceedings of the 2nd International Workshop on Interaction Design in Educational Environments (IDEE-2013), pages 3-13

ISBN: 978-989-8565-65-5

 2013 SCITEPRESS (Science and Technology Publications, Lda.)

be used by architectures, acoustics design engineers, and by infrastructure decision

makers in an early stage of classroom acoustics treatment process to get better objec-

tive judgment about the criteria that could be managed and treated to achieve the

acoustical conditions of KAU university classrooms.

2 Review of Literature

In this section, we explain how the classrooms noise can affect the students learning

process, and how we can avoid that. We also discuss the effective acoustics class-

rooms criteria that we have to be considered into our proposed model.

The relationship between a well acoustically designed classroom and improvement of

scholastic achievement showed that the presence of excessive background noise lev-

els or reverberation in classrooms has a negative impact on academic achievement

and the educational process as a whole [2]. It is shown in [4] that, the main reason of

acoustics problems existing in classrooms is the lack of awareness and understanding

of the problem by the professionals involved in teaching or in classroom design and

the inability to find suitable solutions. The work in [3] stated that the best way to

solve acoustics problems is to avoid them in the design phase. Many researches

proved negative impacts and effects of noise and the lack of clarity of talk and the

lack of speech intelligibility not only on the efficiency of learning and the quality of

teaching but also on the well-being of students and teachers.

Students are impaired by background noise and teachers suffer from raising their

voice level to compensate high level of background noise and increase the signal to

noise ratio (SNR) [5, 6]. On the other hand, if the classroom acoustics were well de-

signed and the acoustical properties inside the classroom were improved this will

result in an improvement on learning and students' behavior, and these results are

registered in numerous studies [7]. In [8], the different aspects that affect the acoustics

quality of classrooms were studied. It showed that location, construction, position or

layout of the of the schools’ recreational areas are important aspects that may affect

speech intelligibility and the learning process in classrooms even if we have a well

acoustically designed classroom. Subjective assessment in [9] showed that both stu-

dents and teachers perceive noise in the classroom and they are bothered by it. It was

found that the acoustics and visual quality inside the classroom have the greatest in-

fluence on the students' learning efficiency. The students were not satisfied with the

quality of ventilation and heating in their classrooms, and acoustical conditions as

well. As a result a bad judgment of the overall quality was concluded.

Speech intelligibility usually interfered with the excessive noise and reverberation

inside classrooms. This cause result in reducing understanding and therefore reduced

student learning and teaching quality. In many classrooms, the speech intelligibility

rating is 75% or less [10]. Which means that, in speech intelligibility tests, listeners

with normal hearing can understand only 75% of the words read from a list. Imagine

reading a textbook with every fourth word missing, and being expected to understand

the material and be tested on it. Sounds ridiculous are exactly the situation facing

students every day in their classrooms.

The work explained in this paper proposes a classroom acoustics assessment model

for enhancing learning quality. The effective weights of all the above acoustics class-

rooms criteria will be taken into consideration in the model proposed in this paper, as

explained in next sections.

3 The CAAM proposed Model

Fig. 1 shows the components of the proposed CAAM model. It consists of five main

criteria that affect the learning process and related to classrooms acoustical properties.

These criteria are developed according to a previous study in [11]. Each criterion is

described by set of alternatives. Twenty eight alternatives are suggested for education

at KAU University. Three levels of hierarchy are constructed, the first level is the

goal of decision model, the second level of hierarchy represents the proposed criteria

that contribute to the goal achievement, and the last level of hierarchy represents the

proposed alternatives that contribute to each of these criteria. Following is a descrip-

tion of each of these criteria.

Fig. 1. The Proposed CAAM Model.

3.1 Classroom Specifications

It's one of the main criteria that affect the education quality. According to our pro-

posed model this criterion includes seven alternatives named A1 to A7 defined as

shown in Fig. 1. Maintaining a good classroom design requires an intensive study for

various classroom specification related to education process. University classrooms

that are used for scheduled classes are not limited in their use for a particular subject

or discipline. Classrooms include general purposes, lecturing classroom, auditoriums,

seminar room, and computer labs [12]. There are numerous factors affect the sound

level in classroom, and hence the sound intelligibility. These include the Adequacy of

space, Lighting, acoustics properties, ventilation, existing equipment inside the class-

room, where the classroom is placed relative to other interior spaces in the building.

For each type, different standard and specifications are required, as follows:

 Acoustic Properties, such as design of walls and ceilings to evenly distribute

sound through the classroom, walls and ceiling acoustical treatment. Preserve re-

verberation time within standard ranges according to the volume of the class-

room. And, to keep ambient noise level less than 35 decibels when measured

with the A-scale of a sound level meter [12].

 Lightening, as stated in [13], "Successful lighting in a teaching environment

should consider the quality, energy efficiency and flexibility of light necessary

for a room – not just the quantity of light. Students and instructor should be sup-

ported with the appropriate luminance level but it should also be the right kind of

light". Although low light levels inside classroom is a problem, too much lighting

is also a problem; too much light can cause difficulties like glare, reflection, eye

strain, etc. Lighting should be designed in accordance with the Illuminating En-

gineering Society's and the National Electrical Code's recommendations.

 Equipment and facilities, each classroom must be minimally-equipped with a data

projector, projection screen, teacher's desktop computer, permanent network con-

nection for students' computers/laptops [13].

 Ventilation, classroom designs must achieve certain level of comfort and effec-

tiveness that will promote optimum conditions for study, listening, reading, and

interaction [13]. Poor ventilation causes students to feel drowsy and not alert.

Proper air flow and ventilation while keep quiet operation of mechanical systems

in classrooms is an important factor [14].

 Classroom Space, if classroom is too small seating capacity will be reduced.

Insufficient classroom space with narrow aisles, too small seats and work surfac-

es, too closed seats are uncomfortable and unacceptable design. Classroom must

be designed to have a good sight lines and efficient seating layouts.

 Classroom Architecture, shape and style, where the building is situated; the size

and shape of the room; its placement relative to other interior spaces; sound re-

flections inside classroom; the number, type, and location of sound sources, and

the strength of the sounds they produce. All of these are important factors that af-

fect the learning process and its quality.

To meet the optimum acoustical quality a careful attention is required to all of the

above factors and specifications, as will be explained in the proposed model.

3.2 Noise Sources inside the Classroom

This criterion includes four alternatives named B1 to B4 defined as shown in Fig. 1.

In order to reduce classroom internal noise, classrooms should be isolated from build-

ing mechanical systems, elevators, restrooms, vending areas, and other noise generat-

ing areas. Heating ventilation and Air condition (HVAC) system are one of the major

sources of noise inside classrooms. That explain why HVAC system requires careful

design, competent installation and balancing, and regular maintenance [14]. Many

factors influence the classroom acoustical design; these include air handlers or fans,

velocity of air inside the classroom, size and acoustical treatment of ducts, returns,

and diffusers. Another source of noise inside classroom is the students themselves;

side discussions, students' activities and interacting increase the noise levels inside

classrooms. Noise generated for lighting equipment and other equipment and facilities

existing in modern classrooms must be also considered. This criterion describes

sources of noise generated within the classroom. Alternatives of this criterion includes

HVAC system, noise generated form students' activity and interacting, lights noise,

and noise generated from smart classroom equipment.

3.3 Noise Sources outside the Classroom

This criterion includes seven alternatives named C1 to C7 defined as shown in Fig. 1.

In order to keep the ambient noise level inside classrooms within acceptable range

classrooms should be separated from noise generating activities outside the class-

room. Sound buffers must be used to reduce external noise, insulating walls, doors

and windows could be used to increase the sound transmission class (STC) rating.

This will reduce the noise level inside classrooms and will separate classrooms from

noisy areas such as streets, parking lots, students gathering area, housing areas, recre-

ation sites, and athletic fields [14]. This criterion describes sources of noise from

outside the classroom. Alternatives of this criterion include traffic noise, noise from

neighboring classrooms, noise coming from corridors, hallways and lobbies, noise

from surrounding playgrounds, any noise comes from exterior mechanical equipment,

aircraft noise, and noise generated from noisy machinery in nearby buildings.

3.4 Teaching Style

This criterion includes four alternatives named D1 to D4 defined as shown in Fig. 1.

Achieving increased effectiveness, efficiency and the enhancement of student learn-

ing is the main goal of all universities. The quality of teaching and learning is totally

depends on the teaching methods and styles used. "Teaching and learning styles are

the behaviors or actions that teachers and learners exhibit in the learning exchange".

Teaching behaviors reflect the beliefs and values that teachers hold about the learner's

role in the exchange. This criterion considers factors related to teaching methods and

strategies and how these factors may affect the learning process. Here, alternatives

include practice work, group work and teaching using blackboard and didactic meth-

od, and using multimedia techniques to deliver course materials. These alternatives

provide different ways of the communication between lecturers and students that of

course affect the learning outcomes. It must be noticed that these alternatives also

affect the noise levels measured inside classroom by different values.

3.5 Vocal Effort

This criterion includes six alternatives named E1 to E6 defined as shown in Fig. 1.

Vocal effort can be defined as the quantity that ordinary speakers vary when they

adapt their speech to the demands of an increased or decreased communication dis-

tance. The communication distance in the previous definition is the distance between

listener and the speaker. Vocal effect also varies if the classroom has noisy condi-

tions. A change in speech mode from whispering to shouting will result due to the

Variation in vocal effort. If the acoustics design of classroom is poor, or the distance

between the lecturer and the students is increased, lecturer needs to speak with a

raised voice level; this may be happened for long periods of time, causing lecturer's

vocal strain. Sound reinforcement systems, lecturer's location inside the classroom

with respect to students, and the number of students inside the classroom affect the

amount of variation in vocal effort. Vocal effort criterion considers alternatives that

may cause this to happen. Alternatives include classroom renovation and acoustics

treatment, using sound reinforcement systems, Location selected by lecturers as their

usual position inside the classroom with respect to students' position, and the effect of

the number of students inside the classroom.

4 The CAAM Model Evaluation

Survey questionnaires are developed to collect information about current situation of

classroom acoustics design at KAU. These questionnaires are adapted from a previ-

ous work in [14]. Two questionnaire are designed, one for students and the other for

faculty members and expertise. Different colleges at KAU have different classroom

sizes with different acoustics classroom designs. The two questionnaires are devel-

oped, reviewed and updated with the assistance of KAU architectural design engi-

neers and acoustics expert consultants. Based on the results from these surveys, the

main criteria and alternatives of the proposed model are identified. Then, the architec-

ture hierarchy process (AHP) [15], is used as a tool for assessment of the weights of

the model criteria and their priority. Table1 shows the main criteria pairwise compari-

son matrix produced using the AHP method. Based on the data collected from ques-

tionnaires, a group of five main criteria with a total of 28 alternatives are identified,

for enhancing service education quality at KAU. Results in Table1 show the main

five criteria, including:

Classroom Specifications (A),

Noise sources inside the classroom (B),

Noise sources outside the classroom (C),

Teaching Style (D) and Vocal Effort (E).

They are ranked with 26%, 23%, 21%, 17%, and 13% due to their importance levels,

respectively. The analyses of these criteria are explained in details next sections.

Table 1. QAAM Main Criteria Pairwise Comparison Matrix.

5 Results and Discussions

Based on the data collected from section 4 above, Table 2 summarizes the results of

CAAM model criteria and the weights of their 28 alternatives, produced by analyzing

the pairwise matrices ;using AHP method; for the five main model criteria.

Table 2. Proposed Standards and criteria of CAAM.

5.1 Room Specification (A)

Seven criteria are used to characterize related room specifications. Both faculty mem-

bers and students were asked to give the importance rating of various criteria of their

classroom. Results are shown in Table 2, where the acoustics properties (listening

environment) of the surveyed classrooms were the most important criteria. It can

affect classroom specifications with a 25% importance level. The second important

criterion for this criterion is the ventilation, with 18% importance level. Lighting is

the third important criterion that can affect room specifications in model with 16%

importance level. Equipment inside the classroom comes in the fourth rank with 13%

importance level. Echo, sufficient classroom space, and classroom shape, architecture

and style have 12%, 8%, and 8% importance level, respectively. Further details of

these ratings in relation to the model design are given in Table 2.

5.2 Noise Sources inside the Classroom (B)

Students and faculty members surveyed reported that noise generated within the class-

room is a big problem that affects the learning process. They have reported that most

of the noise exiting inside the classroom is from the Mechanical Equipment (HVAC)

systems, and the importance level of this criterion is 33% with respect to this criteri-

on. The second source of noise is the students' activity and interaction with an im-

portance level of 25%. Noise coming from lights inside classroom affects the noise

inside the classroom with 22% importance level. Smart classroom equipment like

computers, projectors, keyboards, printers etc. were also identified as common source

of noise generated within new classrooms with an importance level of 20%. Further

details of weights of these criteria related to the model design are given in Table 2.

5.3 Noise Sources outside the Classroom (C)

Another important factor that affects the learning quality inside classroom is noise

that comes from outside the classroom. Students and faculty members surveyed re-

ported problems with noise generated outside the classroom e.g. from traffic, neigh-

boring classrooms, corridors, hallway, lobby, playgrounds and playing fields, exterior

mechanical equipment, aircraft, and noise generated from machinery in nearby build-

ings. Noise from traffic and from other classrooms were the most frequently reported

external noise problems with an importance level of 20% and 18% respectively. Noise

from corridors, hallway and lobby has importance level of 16% with respect to other

sources of noise from outside classroom. Noise from playgrounds and playing fields,

exterior mechanical equipment, aircraft, and noise generated from machinery in near-

by buildings were rate 14%, 12%, 11%, and 9% respectively.

5.4 Teaching Style (D)

One of the key criteria found and has been highlighted by both students and faculty

members in this survey were the teaching style. Traditional lecturing style is no long-

er the dominant style in teaching nowadays. Results showed that practice work has

30% importance level in teaching style for the time being. And, group work has an

equal importance level as blackboard and Didactic teaching style with a value of 25%.

While new technologies and multimedia used in teaching these days has an im-

portance level of 20%.

5.5 Vocal Effort (E)

In our survey faculty members rated the criteria of acoustics treatment as the most

important criterion that may affect the Criteria of Vocal effort with a 22% importance

level. They also rated the sound reinforcement systems criterion with a value of 18%

importance level. The classroom size was reported to affect vocal effort with a per-

centage of 17%. Positions of students inside classroom criterion and lecturer position

inside classroom criterion were rated as 16% and 14% respectively. Finally the num-

ber of students has been evaluated to 13% importance level in terms of its importance

in influencing the vocal effort.

All weights related to each criterion are shown in Table2. An overall ranking for crite-

ria's weights related to the CAAM Model is shown in Fig. 2. It shows that B1” “the

noise from the Mechanical Equipment systems” has the highest noise effect in the

classroom.

Fig. 2. Ranking of all alternatives' weight related to the CAAM Model.

6 Conclusions

Achieving good acoustics design must be consider at the early stages of new class-

room design. Renovating existing classrooms through acoustics treatment will help

improving learning quality and enhance the overall education process by enhancing

speech intelligibility. The work in this paper proposed an acoustics classroom model

for enhancing learning quality. It can help acoustics design engineers, architectures,

and infrastructure decision makers to do a better first step estimates and do a well-

focused study about acoustical problems at KAU classrooms. This will help to take

accurate decisions and to manage the treatment phase in a proper way. The priority

and weights of the model criteria along with their alternatives were identified using

the views of students, staff, education consultants, and expertise using a developed

questionnaire, and the AHP methodology. This model can also be generally used for

other universities and schools as well. The proposed model adds important dimen-

sions and recommendations that have to be taken into considerations in advance be-

fore starting the classroom renovation and acoustical treatment process.

Acknowledgements

This research is done at King Abdulaziz University and funded by King Abdulaziz

University, Deanship of Scientific Research (DSR).

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