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

Acoustic Quality of University Classrooms: a Subjective Evaluationof the Acoustic Comfort and Conditions at the University of Sharjah
Classrooms
Hussein M. ELMEHDI 1; Huda A. ALZOUBI1; Shahzadi Huma R. A. K. LOHANI1
1

University of Sharjah, Sharjah, United Arab Emirates

ABSTRACTIn a previous study, the noise levels in classrooms and lecture halls at the University of Sharjah (UOS), United
Arab Emirates (UAE) were identified as high and in many cases above the standard limits. To assess theeffect of such high noise levels on students, we have conducted a campus-wide subjective survey toinvestigate the effects of such noise on students’ learning experience. The survey aimed at gauging students’
perception of noise levels at various classrooms and impact of noise levels on students’ academic
performance. The results showed that students were able to reliably identify the acoustic conditions thatinterfere with their learning. Strong correlations (R2 = 0.87) between the background noise and persistentnoise and its influence on voice sensitivity. Correlations between noise levels and degree of annoyanceshowed strong relationship between noise levels and percentage of highly annoyed respondents. More than
60% of the students felt that noise interfered with their learning and had an impact on their achievementswith no gender bias, but at lower percentage for advanced classes. In addition, the results indicate thatstudents were not comfortable with the noise in the classrooms including the background noise arising fromvarious internal as well external sources.

Keywords: Noise Levels, Classrooms, Students’ Perception, Annoyance

1. INTRODUCTION

Among the challenges facing postsecondary institutions in recent years is the high students’
expectations related to their experience during their student journey (1). Among the factors that havebeen identified to contribute to students’ experience including lecture delivery, teaching and learning
resources, incorporating latest technological advances into teaching and learning as well as support
services. In addition, and more relevant to the research presented in this paper, is the overall wellbeingof the students that include their satisfaction and comfort with the teaching and learning environment,
i.e. classrooms comfort. The latter has been identified to be influenced by factors such as thermohygrometric, acoustics, and lighting conditions of indoor environments (2). While all factors areimportant, classroom acoustics have received considerable attention in recent years. It has been
identified to have an impact on student comprehension and understanding of the material presented
during the class and hence negatively affect their academic performance (3,4). Poor acoustics were
found to exacerbate the harmful effects of noise and distract students’ attention in class (3-5). Several
researchers have reported that noise has negative impact on the learning capacity of students (4). In
addition, it has been demonstrated that acoustically comfortable environment enhances the
productivity of workers; a finding that can be extended to teaching and learning environment as well(6). Acoustic comfort becomes even more important in interactive learning environments such as
discussion-based, Team Based Learning, etc., where communication among students and instructors
is significant. In a recent study conducted at the University of Helsinki, it was highlighted that students’experience in an indoor environment significantly affects their learning (7). Different classrooms and14130

hmelmehdi@sharjah.ac.ae

learning spaces in general requires special acoustical performance. Acoustic attributes within theclassroom, which included acoustic absorption and highly reflective walls, all affect the learning
process through hindering students’ capacity to hear and communicate with each other and the
instructor. Poor classroom acoustics lead to increase in noise (unwanted sound), which arise fromreflections from classroom surfaces. It tends to disrupt discussions because of high reverberation times
within the classroom. Published literature have reached a common conclusion that classroom acoustics
should be flexible and controllable and background noise must be minimized to promote various
teaching and learning activities.
Classroom acoustics can be evaluated using several variables such as equivalent sound levels, LA eq(in dBA), reverberation times, absorption and transmission noise index. Noise, which is defined as
unwanted sound, is determined by other factors most of which are subjective and depend on theperception of the person. In teaching and learning environment, in addition to measuring the acoustic
attributes, it is very important to gauge students’ perception of the noise levels within the learning
environment and its impact on the learning process. To investigate this, one needs to determine
students’ perception of the acoustics (acoustic comfort) within the learning environment, particularly
the lecture halls. To effectively achieve this, we conducted an online subjective questionnaire, which
comprised of nineteen questions designed to capture the effect of noise on the teaching and learning
process through the students’ perception and satisfaction (acoustic comfort) with the acoustics within
the learning environment. It is therefore the goal of this study to evaluate students’ perception of noisein classrooms at the University of Sharjah, United Arab Emirates (UAE) and investigate possible links
it may have on their academic performance. In addition to onsite measurements of noise levels (dBA)within the classrooms, an online survey was conducted across campus to gauge the students’’perception of noise in university of Sharjah classrooms.

2. MATERIALS AND METHODS

To effectively assess students’ perception of noise in UOS classrooms, we first measured noiselevels in classrooms covering variations in classrooms sizes, dimensions and acoustics attributes, e.g.
insulation, location, seating arrangements. The measurements included background noise, noise levels
during the actual classroom as well as the reverberations times for each classroom. The objective wasto correlate noise levels (both background and noise during the lecture) to the results of the subjective
survey on students’ perception of noise in UOS classrooms. As described in our previous work (8),noise level measurements were conducted in each classroom by carefully selecting a number of points
within the classroom to avoid standing wave locations. This was easily achieved by moving the soundlevel meter around the classroom and look for optimum points. The sound level meter (Sound Level
Meters Nor132) was placed at each point to measure the background noise as well as noise during thelecture and the reverberation times. Before each measurement, the sound level meter was calibratedusing known source, which was supplied by the manufacturer. While the reverberations times were
measured in seconds, the noise levels were measured in dB(A), which is an A-weighted sound levels
used to approximate human hearing by simulating the sensitivity of the average human hearing.
The survey questions were divided into three main parts, the first of which contained generaldemographic questions, i.e. age, college, year of study, type of the lecture. The second part of thesurvey questionnaire focused on noise related questions. These included hearing problems, seating
within the classroom, classroom size, lecture type and instructor voice level. The last part of the survey
focused on students’ perception of noise and its impact on teaching and learning in the classroom. The
questions focused on annoyance due to internal as well as external noise sources. In addition, students
were asked to rate the noise and it impact of their understanding and comprehension of the material
covered in classes. Concluding questions on students’ perception and satisfaction of classroom
acoustic environment were stated clearly to gauge their feeling towards noise within the classrooms.
In total, there were nineteen questions, all of which were required to answer. The survey was designed
and drafted using Microsoft Forms and emailed to all UOS students who were taking classes in theselected classrooms (about 10 000 students) via the UOS intranet. Students can access the survey
using their UOS login credentials. The questions were translated to Arabic and explanations toacoustic terms were provided to avoid misinterpretation of questions. Figure 1 shows examples ofquestions conducted in the survey.

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Figure 1 – Sample questions from the distributed survey

3. RESULTS AND DISCUSSION
3.1 Noise levels and reverberation times measurements
The study focused on six classroom covering different types of classrooms used in UOS from thepoint of view of size, dimensions and functionalities. Background noise level measurements as wellreverberation times were carefully measured/calculated following international protocols taking into
account acoustic attributes for each classroom. The results are indicating that while the backgroundnoise levels ranged from 34 – 52 dB(A), noise levels during the lecture ranged from 59 – 72 dB(A).
Reverberation times were also measured in empty classrooms. The results are shown in Figure 2.
The above results indicate that the reverberation times ranged from 0.54 to 1.2 s, which exceeded
the limits set by the American National Standards Institute (ANSI), which is set at 0.6 s. Rooms withlarge volumes consistently had longer reverberation times as shown in Figure 3. Background noiselevel measurements reveled that only three lecture halls had backgrounds less than 35dBA, and none
had reverberation times lower than 0.4 seconds. The rest of the halls exceeded the recommended
background limits, especially rooms where the HVAC system was on. These results will be discussed
later when correlating the responses of the students.

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Reverberation Time (s)

1.4
1.2
1
0.8
0.6
0.4

y = 0.002x + 0.1704
R² = 0.5789

0.2
0

150

200

250

300

350

400

Classroom Volume (m^3)

Figure 2 – Reverberation times as a function of classroom volume
3.2 Results of Acoustic Satisfaction Survey
As mentioned above the survey was sent by email to over students taking classes on the main UOS
campus. One thousand eight hundred and thirty-four students (n=1834) responded to the survey (23%return rate). Among the 1834 respondents, 76% of which were female students distributed among thevarious university colleges. It should be noted that classrooms at the University of Sharjah are sharedby all colleges and there are no college-designated classrooms. The female dominance is characteristicof the University demographics where more than 64% of the students are females. The respondents’age was dominated by the age group 18-23 years of age as expected. Even though the official languageof instruction at the University of Sharjah is English, 84% of the respondents reported that they takeclasses in English, which is not their native language. The survey revealed that 96% of the students
who took the survey do not have any hearing problems. In addition, it was noticed that students’answers did not depend on class/major. Regarding the student’s seating in the classroom, 47% wereseated in the middle of the classroom, 35% up front and the remaining 22% sat at the back of theclassroom. As expected, the majority of the students felt the large theaters were the noisiest among
UOS classrooms, which varied from small (seating up to 40 students) to large (seats up to 100
students). When students were asked about the main source of noise that effects their concentration
or instructor voice clarity, their responses vary as indicated in the Table 1.
It is clear from the above results that noise outside the classrooms seem to be the highest amongnoise sources and annoyance, instructor’s position in the classroom (15%) and her/his voice (20%)
also interfere with students’ ability to concentrate during the lecture delivery. In a follow-up question,
respondents identified the main source of annoyance within the classroom to be noises from HVAC
system and construction outside the classrooms. Overall, the students positively evaluated theirclassrooms in categories acoustics and echo, showing that they are adequate learning environments.
However, students had negative reactions when asked about noise in the classroom. Students reported
that noise causes discomfort, exteriorized by aggravation and lack of concentration, as well as
consequences on learning (Figure 2). When students were specifically asked to evaluate theinterference of noise with the teaching and learning process, several difficulties were made clear.
These included unclear instructor’s voice and, which limited their understanding of the material andnegatively impacted learning outcome and grades.
The last two questions in the survey focused on noise annoyance within the classroom. Students
were asked to rate their level of satisfaction with classroom acoustics and noise annoyance. Bothquestions used scale of 1 (extremely unsatisfied) – 10 (extremely satisfied). In the case of annoyance,
1 (extremely annoyed) – 10 (not at all annoyed). In Figure 5, we see that both acoustic satisfaction(comfort) and noise annoyance are correlated with R2=0.839. Lastly, noise annoyance was examinedin light of the noise levels (in dB(A)) in the examined classrooms.

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% of Respondents

60
50
40
30
20
10
0

Put extra
effeort tohear

Can not Aggrevation
concentrate

Does notmind

Give uppayingattention

OthersFigure 3 – Students’ reaction when faced with classroom noise (students were allowed to selectmore than one option)
Table 1 – Why do you think it is hard to hear and concentrate in the classroom?
OptionRespondents

The instructor is too far away from the students

269 (15%)

Because of echo in the classrooms

185 (10%)Instructor's voice is not clear or not loud enough

360 (20%)

Students make too much noise

336 (18%)

There is too much noise from outside of theclassroom
There is too much noise from inside of theclassroom
The sounds is too muffled

494 (27%)104 (6%)
86 (5%)

Figure 6 shows that there was the percentage of students who felt highly annoyed strongly dependon the noise levels in the classrooms. Our results indicate that more than 57% of the students reported
that such high noise levels obstructed their concentration and hence effected their understanding andperformance. Our results showed no gender or age bias.
The measured noise levels in the UOS classrooms were generally high. Students felt such noises
interferes with their concentration and overall learning and academic performance. The sources ofnoises in the classrooms were found to come from internal (e.g. HVAC) as well as external sources(e.g. construction). Noise levels within the classrooms ranged between LA eq 58.2.3 dB and LAeq 72.2
dB. Our results are in agreement with similar studies done on examining noise and its effect onteaching and learning activities (9). High noise levels has been reported to hinder students to clearlyhear the instructor (or instructions during the lecture (10,11). According to our findings, students haveidentified noises within the classroom as the main sources of annoyance followed by noise comingfrom the university corridors and people’s voices. This is supported by reports from other studies thatshow that students are aware that they are, themselves, generators of noise, harming class development,
peer concentration and the audibility to hear the teacher’s voice (12,13). When students were asked
about the impact of noise in the classrooms, their responses were: 1. difficulties in hearing the teacher;
2. Interferes with their concentration; 3. Aggravation, all of which are in agreement with reports from4134

% of respondents

similar studies (14,15,16). When students were asked a follow-up question about the consequences ofsuch noise levels, students stated that it led students to give up paying attention, which is of major
concern not only to students but also to the University. In fact, this was one of the main complaints
from students in the exit survey, which prompted the University to launch programs to improve theteaching and learning environment focusing on many students’’ satisfaction attributed (the mostimportant of which is improving classroom acoustics).
20
15
10
5
0

0

1

2

3

4

5

6

7

8

9

10

Acoustics Satisfaction level% of respondents

Figure 4 – Classroom Acoustic satisfaction level (0: not at all satisfied – 10: very satisfied)
20
15
10
5
0

0

1

2

3

4

5

6

7

8

9

10

Annoyance Level

Annoyance

Figure 5 – Classroom noise annoyance level (0: not at all annoyed – 10: very much annoyed)

18
16
14
12
10
8
6
4
2
0

y = 0.7472x + 2.2977
R² = 0.8392
0

5

10

15

20

Acoustic Satisfaction

Figure 6 – Correlation between annoyance and classroom acoustics satisfaction4135

% Highly Annoyed

100
90
80
70
60
50
40
30
20
10
0

55

60

65

70

75

Classroom Noise level (dB(A))

Figure 7 – Relationship between classroom noise levels and percentage of students who felt highly
annoyed.

4. CONCLUSIONS

The results reported in this paper is the first of its kind in the United Arab Emirates, which aimed
at studying students’ perception of noise in the UOS classrooms. This should be taken as an initiative
to encourage other institutions in the country and the region to conduct similar studies to allow us tocompare our results for the purpose of improvement. It is also important to consider the results of ourstudy as a tool to improve the teaching and learning environment and hence improve students’experience during their journey and help the institution achieve excellence in teaching and learningand provide students with quality of life on campus.
The conclusions of our study indicate that UOS students have classified classrooms at the
University to be noisy. They further considered noise as one of the factors that negatively impacted
their understanding and interfered with their communication with the instructor as well as with eachother. This was evident from the fact that over 50% of respondents felt that noises “disrupt their peaceof mind” and over 47% of the students felt that noises “interferes with their ability to hear the
instructors”. A more comprehensive study needs to be conducted to better understand factors
contributing to apparent students’ dissatisfaction with classroom acoustics at the University if Sharjah.
The results of such study will provide the university recommendations on how to improve acoustics
at the teaching and learning environment.

ACKNOWLEDGEMENTS

The authors are very grateful for the financial support provided by the Colleges of Sciences andthe office of Vice Chancellor for Graduate Studies and Scientific Research at the University of Sharjah.

REFERENCES
1.

The
Student
Experience
Survey2018
results.
Availableat:https://www.timeshighereducation.com/student/news/student-experience-survey-2018-results
2. Lee MC, Mui KW, Wong LT, Chan WY, Lee EWM, Cheung CT, Student learning performance 619
and indoor environmental quality (IEQ) and air conditioned university teaching rooms. Build 620
Environ 2012; 49: 238-244.
3. Buratti C and Ricciardi, P. Adaptive analysis of thermal comfort in university classrooms:
correlation between experimental data and mathematical models, Build. Environ. 44 (2009) 674–
687.
4. Knecht HA, Nelson PB, Whitelaw, G.M., Feth, L.L., Background noise levels and reverberation
times in unoccupied classrooms: predictions and measurements, Am. J. Audiol. 11 (2) (2002) 65–
71.
5. Sato H, Bradley JS, Evaluation of acoustical conditions for speech communication in4136

working elementary school classrooms, J. AcoustSoc Am. 123 (4) (2008) 2064–2077.
6. Shield BM, Dockrell JE, The effect of environmental and classrooms noise on the academic
attainments of primary school children, J. AcoustSoc Am. 123 (2008) 133–144.
7. Yang W, Bradley JS. Effects of room acoustics on the intelligibility of speech in classroom foryoung children, J. AcoustSoc Am. 12 (2010) 225–234.
8. Elmehdi HM. Assessing noise levels in University of Sharjah lecture halls using measurements andpredictive models. Inter-Noise 2018. August 26-29, 2018. Chicago Elonis, UAS.
9. Klatte M, Lachmann T, Meis M. Effects of noise and reverberation on speech perception andlistening comprehension of children and adults in a classroom-like setting. Noise Health.
2010;12(49):270-82.
10. Woolner P, Hall E. Noise in schools: a holistic approach to the issue. Int J Environ Res Public
Health. 2010;7(8):3255-69
11. Johnson CD, Meinke DK. Noise-induced hearing loss: implications for schools. Semin Hear
2008;29(1):59-66.
12. Shield BM, Dockrell JE. The effect of environmental and classrooms noise on the academic
attainments of primary school children. J AcoustSoc Am 2008; 123: 133-144.
13. Yang W, Bradley JS. Effects of room acoustics on the intelligibility of speech in classroom foryoung children. J Acoust Soc Am 2010; 12: 225-234.
14. Hodgson MR. Experimental investigation of the acoustical characteristics of university classrooms.
J AcoustSoc Am 1999; 106: 1810-1819.
15. Kennedy SM, Hodgson M, Edgett LD at all. Subjective assessment of listening environments inuniversity classrooms: perception of students. J AcoustSoc Am 2006; 119: 299-309.
16. Zannin PHT, Marcon CR. Objective and subjective evaluation of the acoustic comfort inclassrooms. Appl Ergon 2007; 38: 675-680.

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