The use of and attitudes to voice amplification in higher education institutions

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EXAMENSARBETE INOM MEDICINSK TEKNIK, AVANCERAD NIVÅ, 15 HP

STOCKHOLM, SVERIGE 2019

The use of and attitudes to

voice amplification in higher

education institutions

Användning av och attityder mot

röstförstärkning i högskolor

JOSHUA DAVID ASHOK

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The use of and attitudes to voice amplification in higher

education institutions

Användning av och attityder mot röstförstärkning i högskolor

Joshua David Ashok

Master Thesis in Medical Engineering

Supervisors: Svante Granqvist, Annika Szabo Portela Examiner: Mats Nilsson

KTH Royal Institute of Technology

School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH) 141 52 Huddinge

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ABSTRACT

Background: Voice is still the most important tool used by teachers, but voice is varied and subject to problems. Teachers who lecture for long hours or have taught for most of their professional lives, face issues such as voice discomfort, chronic voice disorders, occupational voice disorder, stress, physiological and psychological problems. Due to issues such as poor acoustics in the classroom and absence of any installed voice amplification system, teachers might be subject to increase their vocal load to reach all the students in the classroom.

Purpose: The aim of this study is to study the fundamental frequency (fo) and the strength

Leq[dB(C)] of the teacher’s voice, with and without voice amplification system.

Method: Students from the preparatory year of their studies at KTH (CBH), were asked if they would like to participate in this study that researches on the voice health of teacher. Two days of teaching sessions were recorded using a microphone attached to the teacher’s mouth and three other static microphones placed in different parts of the room. The voice amplification system used in the study, was the one that was already in use at some of the classrooms at KTH. The students and the participating teacher were given questionnaires, towards the end of the teaching session to voice their opinion on the teaching voice, with and without the voice amplification system.

Results: The results from the data collected from the recordings, have shown that the SPL increased between 0.6 dB(C) and 5 dB(C) when the voice amplification system was turned on. The fundamental frequency (fo) of the teacher’s voice reduced by 1.4% with the use of the voice

amplifier. The response of the students was overwhelmingly in support of the voice amplification system used during the recordings. 60-62% of female respondents and 68-79% of male respondents felt that the voice amplification system increased the audibility in the classroom.

Conclusion: Leq [dB(C)] values from the mics around the classroom showed a considerable

increase and thus the amplification system provides a good acoustic condition for the teacher to communicate with his students and a significant improvement in student’s comprehension of the teacher’s voice and learning conditions. There was a decrease in the fo of the teacher’s

voice with the amplification, which is good for the teacher’s vocal health and reduces voice disorders while improving the quality and audibility of teacher’s voice. Majority of the students felt that the amplification system was beneficial during the teaching sessions and would like to see more amplifiers installed in more classrooms.

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SAMMANFATTNING

Bakgrund: Rösten är fortfarande det viktigaste verktyget som en lärare har, men rösten är varierad och utsatt för en del problem. Lärare som har undervisat i hela sina professionella liv, står inför problem som obehag med sin röst, kroniska röstförluster, yrkesskador, stress, fysiologiska och psykiska problem. På grund av dålig akustik i klassrummet och frånvaron av ett installerat röstförstärkningssystem, kan lärare bli tvungna att öka sin röstvolym för att nå alla elever i klassrummet.

Syfte: Syftet med denna studie är att studera den grundläggande frekvensen (fo) och styrkan

Leq[dB (C)] i lärarens röst, med och utan röstförstärkningssystem.

Metod: För studenter från basår på KTH (CBH) blev frågan om det skulle vilja delta i denna studie som undersöker lärarens rösthälsa. Två dagars undervisningsspel registrerades med hjälp av en mikrofon kopplad till lärarens mun och tre andra stationera mikrofoner med stativ placerades i olika delar av rummet. Det röstförstärkningssystem som användes i studien var det som redan var i bruk vid några av klassrummen på KTH. Eleverna och den deltagande läraren fick frågeformulär mot slutet av undervisningssessionen, för att svara på frågor om lärarens röst, med och utan röstförstärkningssystem.

Resultat: Resultatet som samlats in från inspelningar visade att SPL ökade mellan 0,6 dB (C) och 5 dB (C) med röstförstärkningssystemet. Den grundläggande frekvens (fo) av lärarens röst

minskade med 1,4% med röstförstärkaren. Svaren från eleverna var ett överväldigande stöd för röstförstärkningssystemet som användes under inspelningarna. 60-62% av det kvinnliga respondenterna och 68-79% av det manliga ansåg att röstförstärkningssystemet ökade hörbarheten i klassrummet.

Slutsats: Leq [dB (C)] -värdena från mikrofonerna på olika ställen i klassrummet visade på en

avsevärd ökning av hörbarheten och gav därmed förstärkningssystemet en bra akustisk möjlighet för läraren att kommunicera med sina elever och en signifikant förbättring när det gäller studentens förståelse av det som läraren ville förmedla. fo värdena minskade genom

förstärkningen, vilket var bra för lärarens vokalhälsa och minskade ohälsan samtidigt som lärarens röst och kvalitet förbättrades. Flertalet studenter kände att förstärkningssystemet var fördelaktigt för undervisningen och skulle vilja se förstärkare installerade i flera klassrum.

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ACKNOWLEDGEMENTS

I thank Dr. Annika Szabo Portela, for her assistance in helping me choose this particular subject of teacher’s voice health, her endless help in gathering information for me to do the preparation and structure for this study.

I thank Dr. Svante Granqvist, who has been my steadfast support, while recording the lectures, spending time in the evenings to teach and advise me on the softwares and guiding me all the way through this study.

I thank the students, who voluntarily took part in the study and gave their feedback, to better understand a student’s point of view on voice amplification in higher education institutions.

Special thanks to my mother, father, sister and friend CE Weber for their continued support in my decision to finish the thesis.

I take this opportunity to remember my late friend Alexia Conyers, for the faith she had in me.

Last but not least, I thank my Guillermo and our Barney for pushing, encouraging and supporting me, in this life’s most important journey.

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GLOSSARY / ABBREVIATIONS

SNR Signal to Noise Ratio

SPL Sound Pressure Level

fo Fundamental Frequency

Leq Equivalent Continuous Level

Leq[dB(C)] C Weighted Sound Level

Sopran Sound Editor. Used in the analysis of SPL.

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1. BACKGROUND

A well-functioning voice is an essential tool for one third of the labour force and vocal demands vary to a great extent between the different voice and speech professions (Vilkman, 2004). Voice is still the most valuable feature used by teachers to communicate with their students, despite an era where e-books and online teaching have become more common. Both schools and universities, heavily depend on voice use, that nurtures and seeds ideas into the minds of future engineers, doctors, etc.

According to (Viveka Lyberg Åhlander, 2014), one of the most important aspects of teaching is for the teacher to make herself or himself heard. The demands on a teacher’s voice are varied. The voice is needed to communicate, instruct, and clarify. Voice problems in teachers are subject to issues such as inability to deliver an audible lecture due to vocal discomfort, chronic voice disorders, occupational voice disorders, poor acoustics at the teaching environment, physical or mental barriers, etc. This in turn can cause problems to students such as difficulty in hearing the teacher clearly, distractions caused due to the lack of motivation in the classroom, etc.

1.1.Environmental challenges

In most learning environments, the most important consideration for accurate speech perception is not the type of noise or overall background noise level, but, rather, the relationship between the intensity of the signal and the intensity of the background noise at the child’s ear. This relationship is often referred to as the signal-to- noise ratio (SNR) (Carl C. Crandell, Classroom Acoustics for Children With Normal Hearing and With Hearing Impairment, 2000). One should also take into account, that not all students are the same because some are hyperactive in the classroom and some are non-hyperactive.

According to (Sydney S.Zentall, 1980), hyperactive children perform tasks in the classroom that are differentially harder for them than for non-hyperactive children, classroom noise probably adds an additional burden, especially when it overlaps a task requiring some auditory processing of information (e.g. memory). According to (W. Yang, 2009), an ideal approach to the acoustical design of classrooms would be to first reduce all noise levels at the source if possible and then design the reverberation time of the room to optimize the provision of added reflected sound to enhance speech levels. Ambient noise levels within a classroom can interfere

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2 with both teaching and learning. Noise sources include such things as heaters, air conditioning, radio, television, and students moving and talking (Jana Addison, 1999). Speaking over noise, changes the spectrum of the voice as compared to the typical voice and may result in an increase or decrease of noise in the higher part of the spectrum (Viveka Lyberg-Åhlander K. J., 2015).

1.2.Effects of voice disorders

Voice problems are common among teachers (Valdis Jo ́nsdottir, 2001). Teachers had a significantly increased occurrence of voice disorders compared with other occupations. A large variation in reported prevalence of voice disorders was observed (Lady Catherine Cantor Cutiva, 2013). Research by (Nelson Roy R. M., 2005) states that, voice disorders are presumably related to acute and self-limiting infectious processes, others appear to be chronic and linked to specific social or occupational voice use patterns, medical conditions, and other factors, which increase vulnerability for experiencing a voice disorder.

Teachers are required to use their voices both as an educational and disciplinary tool, often in difficult circumstances. They frequently have to teach in rooms where the acoustics are poor, where they are surrounded by noise and where they are often at too great a distance from their pupils (Valdis Jo ́nsdottir, 2001). Some teachers may not even be aware of the fact that they have voice disorder due to increased vocal use in the classrooms and need medical help. According to (Nelson Roy R. M., 2004), teachers may be reluctant to take time off from work for medical appointments or may fear that physicians may admonish them to reduce voice use at work, stop teaching altogether, or change occupations. The effects of voice disorders can directly or indirectly affect the job performance and attendance of teachers. This tendency of the teachers who don’t want to seek help should be explored more in detail in further research. Research by (Bridget Shield, 2015) describes how relationships between lesson noise levels and unoccupied acoustic conditions emphasize the necessity of considering the acoustic conditions in all teaching spaces in a school at the design stage of a building or its refurbishment. Speaking in various rooms leads to different experiences or sensations for a talker, due to changes in auditory feedback.

1.3.Vocal effort

The vocal effort required for communicating with a listener at different distances changes with room acoustic conditions, as does also the feeling of vocal comfort (David Pelegrin Garcia,

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2011). Noise that students make also plays a vital role in maintaining the vocal pitch of the teachers while lecturing. The measured noise levels in occupied classrooms are largely due to the direct and early reflected sound from nearby student activity and can only be controlled at the source. It is therefore important that teachers appreciate the need to control student noise when important information is to be orally communicated (Hiroshi Sato, 2008).

Research by (Annika Szabo Portela S. G., 2018) emphasizes that, reducing background and activity noise levels should be the first intervention to improve voice ergonomic conditions in communication-intensive and vocally demanding workplaces. Teachers who work in noisy classrooms, teach physical education, or use a loud speaking voice are at greater risk of associated voice disorders (Cantor Cutiva, 2013).

Building hi-tech and fancily furnished institutions are important indeed, but the fact is that educational institutions haven’t looked properly into the sound and noise problems at teacher’s work environment. According to (Viveka Lyberg-Åhlander R. R.-G., 2015) the focus has mainly been on the listeners and the sound environment in general, not so much on teachers’ voice use and the consequences of vocal problems.

Prolonged voice use, through verbal instruction, often in the presence of background noise, has been implicated as a cause of vocal impairment among members of this profession (Elaine Smith, 1998). The attention towards the problems among teachers has been more connected towards student’s attention and their academic progress, but less attention has been given on the teacher’s voices.

In order to draw attention to teacher’s vocal load in classroom environment, studying the impact of voice amplification is a valuable contribution. According to (Leena M. Rantala, 2015), if the ambient noise in a classroom is loud, the teacher uses a louder voice even before work, and perturbation values are higher than among those working in quieter working environments and male teachers use lowered voice pitches under loud ambient noise. Teacher’s voice SPLs change less and spectrum slopes steepen more (reflecting more hypofunctional voice quality) while working in high activity noise levels than while working in lower activity noise levels.

Lecture halls, which are often credited as high standard, should be given a thorough check if students can really hear the teachers or if teachers have to shout louder in order to be heard by

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4 everyone in the classroom. There are numerous studies conducted in kindergarten, primary and secondary schools, but so far very few in university environment.

1.4.Amplification systems

An amplification system or a dynamic sound field system, involves the use of one or more amplifiers connected to microphones in close proximity to the teacher. Using a properly installed soundfield system could be a good choice for both faculty members and students. Amplifiers have been in use since its invention by Lee De Forest in the early 20th century.

Research by (Jeffery B. Larsen J. C., 2008) , states that the purpose of a classroom amplification system is to amplify a teacher’s voice in the classroom setting and create a favorable signal-to-noise ratio (SNR), meaning that the teacher’s voice is more intense than the competing background noise in the classroom. In other words, an equipment that strengthens a weak voice to become louder or stronger, without interfering with the clarity of the voice.

According to (Aline Duarte da Cruz, 2016 ), the use of a dynamic soundfield system was effective for improving the students’ academic performance on standardized tests for reading, improving the teacher's speech intelligibility, and reducing the teacher's vocal strain. One should also take into account the distance between the teacher and the student. At distances relatively close to the child, the direct sound field predominates in the listening environment. In this sound field, sound waves are transmitted from the teacher to the child with minimal interference from room surfaces (Carl C. Crandell, 2000).

Use of voice amplifiers can be integrated with a fixed sound field system in the classroom. The teacher uses a microphone that produces a louder voice through the conversion of electric signals to sound signals.

Teacher using Microphone Amplifier Speaker

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Research by (Jeffery B. Larsen A. V., 2008) , states that young adult listeners benefited from the sound-field amplification system over listening to the low-intensity speech signal in the unamplified condition and efforts to improve the acoustic conditions of post- secondary classrooms can significantly benefit college students, especially when listening in very poor SNR conditions in a classroom.

According to (Shield, 2012) sound-field systems should create a more favorable signal-to-noise ratio (SNR) than is generally available in the classroom. Different parameters such as sound

pressure level (SPL), fundamental frequency (fo) and speaking time (phonation) can be

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2. PURPOSE

The purpose of this project is to explore a teacher’s voice use in higher education setting through acoustic analysis of voice and noise SPL Leq [dB(C)], speaking fundamental frequency (fo), with

and without the use of voice amplification in different classroom environments and teacher’s and student’s perception of vocal loading and audibility by means of questionnaires.

3. METHODOLOGY

This project involves various steps such as, choosing a group of participants to take part in the study as a group, getting approval from participants to record the teaching sessions, sending out questionnaires to participants before and after the use of a voice amplification system, comparing the results and analyzing the data gathered in the recording process. The recording took place at two different classrooms at KTH, School of technology and health, at two different occasions, without and with the amplification system.

3.1 Material

Two different classrooms equipped with an already installed voice amplification system were chosen at KTH (CBH). The voice amplification system used during the classroom recordings was AKG: CU800. It’s a digital wireless microphone amplification device used to process signal transmission in lecture halls, conference rooms and theaters. This amplification system consists of a voice amplifier, microphone (connected to the participating teacher’s mouth) attached to a pocket transmitter and loudspeakers.

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The classrooms were set up with 3 pre-polarized Omni condenser microphones placed at different locations. The microphones used were, OM1 manufactured by Line Audio Design. They were placed on static microphone stands, one close to the speaker (participant teacher),

one in the middle of the classroom and one at the very end of the classroom.

Fig 4: OM1 Omni condenser microphone (Line Audio Design, n.d.) Fig 5: JBL loudspeaker (Photo courtesy: Joshua David Ashok)

The 3 static OM1 microphones were connected to a Zoom H6 recorder. The teacher lecturing had the microphone to the mouth, and it was connected to a Zoom H4n recorder. The data recorded was saved in SD cards and then transferred to work computer.

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8 Dr.Svante Granqvist, participant teacher in this project, wearing an AKG: pocket transmitter wirelessly connected to AKG:CU800 voice amplification system. The pocket transmitter is connected to microphone (black) on the right side of his mouth. Another microphone (white) on the left side of his mouth is connected to Zoom H4n recorder, which he is holding in his hands. Picture was taken on the last day of the recording sessions.

Fig 8: Dr.Svante Granqvist, Assistant Professor, Grundläggande Naturvetenskap, Program Director (Technical Preparatory Year) at KTH, Fleminsgberg and also the participant teacher in this project.

Photo Courtesy: Joshua David Ashok

3.2. Calibration

Both the recorders Zoom H4n and Zoom H6 were calibrated. The Zoom H4n was calibrated at a distance of 30cm from the microphone next to the teacher’s mouth. The Zoom H6 was calibrated by placing all 3 static microphones together, very close to the calibrating device (sound level meter).

3.3. Recordings

The recordings took place at two different occasions at two different rooms. The first recording session took place at 10.00AM on the 19th of November 2018, first without the amplification

system. After a teaching session of 45 minutes and 15 minutes of break, the amplification system was turned on and the recording happened for another 45 minutes. The same procedure was repeated at another teaching session that took place at 10.00AM on the 24th of November

2018, in a different room with the same amplification system. The students and the teacher were issued the questionnaires towards the end of each teaching sessions and were asked to give their opinion on the vocal loading and the audibility of the teacher’s voice, with and without the amplification system.

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3.4. Software

In order to run the acoustic analysis of the data collected during the recording sessions, three different software were used. They were Sopran, RecVox and MATLAB. Sopran and RecVox were created by Dr.Svante Granqvist, assistant professor at KTH, Flemingsberg and are copyrighted under Tolvan Data. Sopran is a software that is primarily used to process and analyze sound files, acoustic analysis of voice and noise files SPL, involves various features such as voice source measurement, generating spectrograms, inverse filtering and involves the

use of (.wav) files. Sopran is available at,

http://www.tolvan.com/index.php?page=/sopran/sopran.php. RecVox is primarily used to generate phonetograms and different parameters such as fo, SPL, etc. It involves the use of

(.smp) files that are generated through Sopran. The phonetograms are generated as (.stdpg) files. RecVox is under construction and kindly look out for more updates on it for future projects. MATLAB was used to split (.wav) files that were too big to process in Sopran.

3.5. Ethical vetting

Before the recordings, Dr.Svante Granqvist, assistant professor at KTH Flemingsberg and also the participating teacher in the voice recordings, informed the students about the project and received their consent. The recordings took place during normal class hours.

3.6. Participants

The student group chosen as participants were doing their preparatory year (year before being admitted to KTH for their bachelor studies). The first recording session included a group of 30 students, 8 females and 22 males, with 29 students between the age group of 18-30 and one between 31-50. The second recording session included a group of 26 students, 5 females, 2 others and 19 males, with 25 students between the age group of 18-30 and one between 31-50. The participant teacher was between the age group of 51-70. The students were interested in being recorded and voluntarily accepted to take part in the study. They were given the choice to voice their opinion if they didn’t want the recording to happen. Once they let agreed to be a part of the study, they were promised that the questionnaires will remain anonymous. The only personal details that we received from the participants were, age, sex and if they have any self-reported hearing impairments.

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10 3.7. Questionnaire

A set of questions were prepared and handed to the thesis supervisors. After careful reading, corrections and considerations, the questionnaires were printed out to be given to students towards the end of each teaching / recording session. The questionnaires were constructed in such a way, that the students can voice their opinion on their teacher’s vocal load, audibility and noise absorption / disturbances in the classroom, etc. The questionnaires were divided into two different categories such as, opinions before the use of voice amplification system and opinions after the use of voice amplification system. Another set of questionnaires was prepared for the participating teacher in the project. The following questions were presented to the students to receive their opinion.

Table 1: Questions asked before the use of voice amplification system Your gender

Your age

Is your classroom equipped with amplifying system? Do you have any diagnosed hearing impairment? Was it hard to hear the teacher?

If “Yes”, do you think that using voice amplification would make a difference? Does your teacher sound healthy?

Do you perceive that your teacher’s voice causes issues such as difficulty in concentrating / hearing or anything else?

How would you rate the acoustics in the room? (e.g. carpets, curtains, noise proof windows / doors, use of amplification systems, movement of teacher around the classroom, etc.)

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Table 2: Questions asked after the use of voice amplification system

Did you find it beneficial to have an amplifier installed in your classroom for lecture? How do you perceive the amplification system?

Did the amplified voice increase audibility? How would you rate your teacher’s voice?

Have you noted any changes in your fellow student’s behaviour such as concentration / attention, since the use of amplifier?

Would you like to see voice amplification systems installed in more classrooms?

The following questions were presented to the participating teacher to voice his opinion on his teaching methods in the classroom, vocal load, voice audibility / pressure, etc.

Table 3: Questions asked to the teacher, before the use of amplification system Gender

Age

Any prior teaching experiences? Specify if any and how long. Have you undergone teacher’s training program?

How many hours of teacher’s training did you undergo (approximately)? Specify your level of education

How many hours do you teach every week/month (approximately)?

Have your students shown any sign of listening or understanding difficulties? Do you ask for your students for feedback at the end of a lecture or course?

What kind of feedback do you usually receive, apart from the content of the lesson?

Do you move around while lecturing in the classroom, in order to reach students in all corners of the classroom?

Do you think that the use of amplifying system would have any impact on your teaching? Would you like to take part in our experiment regarding the use of amplifiers in classrooms?

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12 Table 4: Questions asked to the teacher, after the use of voice amplification system

Do you think that having an amplification system in the classroom, benefits you? Did you feel comfortable having to use an amplifier in the classroom?

From what perspective would you rate the amplifying system in your classroom?

Do you think that students at the very end of the classroom were able to hear, understand clearly or concentrate better?

How do you believe your amplifier benefits your students or not?

Do you think an amplification system could be beneficial to you and other teachers, if installed in all classrooms? Should the university spend on buying amplification systems for all classrooms in the campus?

Specify if you have any suggestions in regard to the use of voice amplification in teaching in higher education institutions.

Copy of questionnaires to the students and the teacher are available in the appendices section. 3.8. Analysis

Before the sound files in (.wav) format could be loaded into the software program, they had to be split into smaller files as the recorded data were saved in large files, moreover Sopran can process only 250 million samples at a time. MATLAB was used to split the (.wav) files. Once the sound files were in the accepted range to be loaded, the software program Sopran was used to import (.wav) files that were recorded using the recorders Zoom H4n and Zoom H6. Sopran is used to analyze and process the voice and noise files SPL, hence it can be called a sound editor. The idea was to analyze the different parameters such as (SPL) Sound Pressure Level and (fo) Fundamental Frequency, where (fo) could be analyzed using the other software program

RecVox. The sound files from Zoom H4n were recorded, at a distance of 4cm from the speaker’s mouth. The sound files from Zoom H6 were recorded at three different locations (front, middle and back) of the classroom to check the vocal load and audibility of the teacher’s voice. Once the sound files in (.wav) format were loaded in Sopran, respective calibration sound files were added to them to be formed into one single spectrum. The first step involved calibrating the calibration (.wav) file by choosing a part of it. When this data is given to calibrate in Sopran,

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the whole file in Sopran gets calibrated to Pascal (Pa), the unit of pressure. Using the log measurements, one can take out the necessary parameters such as the equivalent continuous level of sound (Leq), Leq [dB(A)], Leq [dB(C)] and dB re FSD. Leq is the preferred method to

describe sound levels that vary over time, resulting in a single decibel value which takes into account the total sound energy over the period of time of interest (Associates, n.d.). For the standard threshold of hearing, the intensity of sound is measured in dB. dB(A) stands for (A) weighting sound level and also described as contour filter. dB(C) stands for (C) weighting sound level. (C) weighting is usually used for peak measurements, since the human ear flattens the noise level above 100 dB or more. Once the sound measurements (SPL) are taken out of Sopran, the resulting data can be saved in (.smp) file format. This (.smp) file can be loaded into RecVox, to generate phonetograms. Different sound files can be compared with different colors and can even be overlapped to compare the fundamental frequency (fo) of the speaker’s

voice, both without and with the use of the amplification system. Below is a flowchart representing the various stages of the recording and voice analysis.

Participants (Students/Teacher) Approval for voice recordings

in the classroom Recordings with Zoom H4n and Zoom H6 at 2 different

sessions

Questionnaires

Data categorisation, usage of Matlab to split files

Use of Sopran and RecVox

Comparison of variables Leq- Equivalent continuous level Leq[dB(C)] - C weighted sound level fo- Fundamental frequency

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4. RESULTS

The results are classified into two groups, such as results from the acoustic analysis and results from the questionnaires answered by the students and the participating teacher. The acoustic analysis was carried out on the (.wav) files that were recorded on two different days, Day 1 (first without and then with the use of sound amplification system) and Day 2 (first with and then without the use of sound amplification system).

4.1. Acoustic analysis - Day 1 and Day 2 recordings

Table 5: SPL values correspond to the recordings in the microphone placed near the teacher’s mouth and 3 static microphones placed at three different locations in the classroom.

Microphone Position Day 1 Day 2 SPL without amplification [dB(C)] SPL with amplification [dB(C)] SPL with amplification [dB(C)] SPL without amplification [dB(C)] Near teacher’s mouth 70.9 70.9 70.1 72.5 Front 60.8 49.7 * 71 66 Middle 73.7 75.2 63.7 62.6 Back 48.2 46.9 * 68.4 67.8

Note: * sign on the SPL values from Day 1 recordings, shows reduced Leq [dB(C)] values. This reduction in the

SPL values with the use of amplifier, could have been caused due to improper handling of volume and signal input settings, in the Zoom H6 recorder. Therefore, the author has chosen Day 2 values for results and conclusion.

Results obtained from table 5 suggests that, with the use of voice amplification system, there was no change in the voice of the teacher on day 1 but a slight decrease of 2.4 dB(C) on day 2. On day 1, with the use of the amplifying system, the front mic shows a decrease of 11.1 dB(C) but increased by 5 dB(C) on day 2. The middle mic shows an increase of 1.5 dB(C) and 1.1 dB(C) on days 1 and 2 respectively with the amplifying system. The back mic shows a decrease of 1.3 dB(C) and an increase of 0.6 dB(C) for days 1 and 2 with the amplifying system.

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Table 6: Fundamental frequency fo values correspond to the recordings in the microphone

placed near the teacher’s mouth.

On day 1, the fundamental frequency of the teacher’s voice without amplification system was 141.5Hz and reduced by 1.4% after the use of voice amplification system in the classroom. On day 2, the fundamental frequency with the amplification system was 131.6Hz but it increased by 8.6% when the amplification system was turned off.

The following figures are examples of pictorial representation of the data analysis done in the software program Sopran, for SPL – Leq [dB(C)]. Fig 9 in black denotes the recording of the

teacher’s voice without the use of amplifying system and Fig 10 denotes the recording of the teacher’s voice with the use of amplifying system. The files are calibrated to Pascal (Pa) and it represents the signal processing and the maximum amplitude a signal can reach. One can observe that the peak amplitudes of the file reaches just above 2 Pa on both sides of the spectrum. The log measurements can also be seen from where SPL is derived.

Fig 9 Fig 10 Microphone position Day 1 Day 2 fo without amplification [Hz] fo with amplification [Hz] fo with amplification [Hz] fo without amplification [Hz] Near teacher’s mouth 141.5 139.1 131.6 144

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16 The following figures are pictorial representations of data analysis done in software program, RecVox for fundamental frequency (fo). Red denotes without amplifying system, blue denotes

with amplifying system.

The recordings that are SPL calibrated are mainly used in RecVox to derive phonetograms. One can observe the difference in voice modulation in real time in the figures below. The concentration of colors in the figures suggest that the speaker had a steady flow of voice with a few ups and downs in SPL at different ranges. The more the concentration of the color, the more that speaker was in the same range of frequency. Fig 11 represents the (fo) of the teaching

voice without the use of amplification system, Fig 12 represents the (fo) with the use of

amplification system. The fundamental frequency of both the amplified and unamplified can be seen overlapping each other in figure 13.

Fig 11 Fig 12

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4.2. Questionnaire comparison

The questionnaires were made for both the students and the participating teacher. The students were issued the questionnaires at the very end of their teaching session and asked to voice their opinion. The feedback was collected and tabled in percentage. Questions that weren’t answered by the students, are marked by (-) symbol.

Table 7: Collection of questionnaire feedback given by the students, on day 1 and day 2, without the use of sound amplification system.

WITHOUT AMPLIFIER Day 1 (%) Day 2 (%)

Gender Female Male Female Male

Answers (Yes/No, Good/Bad) Yes No Yes No Yes No Yes No

Classroom equipped with

amplifying system? 100 0 86 14 60 40 74 26

Hearing impairment? 0 100 0 100 0 100 0 100

Hard to hear the teacher? 0 100 4.5 95.5 20 80 16 74

If "Yes", amplifier would make a

difference? 12.5 - 23 - 20 - 37 5

Does teacher sound healthy? 75 25 91 9 60 40 89.5 10.5

Teacher's voice difficult to

concentrate? 12.5 75 9 77 20 80 21 53

Rate the acoustics in the room

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18 Table 8: Collection of questionnaire feedback given by the students, on day 1 and day 2, with the use of sound amplification system.

WITH AMPLIFIER Day 1 (%) Day 2 (%)

Gender _Female _Male _Female _Male

Answers (Yes/No/Not sure,

Good/Bad) Yes No/Not sure Yes No/Not sure Yes No/Not sure Yes No/Not sure Was it beneficial? 100 0 64 32 80 20 74 16

How do you perceive

amplification? (Good/Bad) 100 0 95.5 4.5 100 0 89 -

Did the amplified voice

increase audibility? 62.5 37.5 68 27 60 20 79 10.5

Rate the teacher's voice

(Good/Bad) 50 50 73 23 60 40 74 16

Do fellow students

concentrate more now? 37.5 62.5 23 68 60 40 10.5 79

Should we have amplifiers in

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Table 9: Collection of questionnaire feedback given by the participating teacher, on day 1 and day 2, without the use of sound amplification system.

WITHOUT AMPLIFIER COMMENTS

Gender Male

Age 51-70

Any prior teaching experiences? Specify Yes, 28 years

Undergone any teacher's training? Yes

How many hours of training was it? 400 hours / 15hp

Education level PhD

How many hours do you teach? 12 hours/week

Do students show any sign of understanding difficulties? No

Do you ask for your student’s feedback? Yes

Do you get comments on your voice or any hearing issues? No

Do you move around in the classroom while teaching? Sometimes

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20 Table 10: Collection of questionnaire feedback given by the participating teacher, on day 1 and day 2, with the use of sound amplification system.

WITH AMPLIFIER COMMENTS

Does the amplification system benefit you?

Yes Did you use the microphone to teach?

Yes, I used the microphone

Do you feel comfortable having to use an amplification system? Yes

From what perspective would you rate the amplification system? Positive, Unusually good

Were the students at the back able to hear or concentrate better? Yes

How do you think the amplifier benefits your students? Better audibility, less sensitive to

student's noise

Would the amplification system be beneficial to other teachers? Yes

Should the university install amplifiers in all classrooms? Yes

Any suggestions in regard to the use of amplifiers at universities? Easy to handle, no volume controls,

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5. DISCUSSION

This study is one among the first to examine the effects of the use of voice amplification system in higher education institutions. The aim of the study was to explore a teacher’s voice use in higher education setting through acoustic analysis of voice and noise SPL - Leq [dB(C)],

speaking fundamental frequency (fo), with and without the use of voice amplification in

different classroom environments and teacher’s and student’s perception of vocal loading and audibility by means of questionnaires.

There were quite a few significant findings such as, the voice uses by a teacher, differences in the speaking fundamental frequency (fo) of the teacher’s voice, possible attitude changes in

regard to the use of voice amplification system and sound pressure level (SPL) in the classroom.

In Table 5, the Day 1 (SPL) values shows some differences in the microphones placed in different parts of the classroom. With the amplification system turned on in the second half of the teaching, there was an increase in SPL in the middle mic by 1.5 dB(C), but the mics placed in the front and back of the classroom showed decreased SPL values. This could mean that the students seated in the middle of the classroom had a better clarity of the teacher’s voice, when the voice amplification was turned on.

On the Day 2 of recordings, the SPL values increased on all three static microphones between 0.6 dB(C) and 5 dB(C) with the voice amplifier. This is an increase in the strength of the teacher’s voice. The SPL fluctuated by increasing and decreasing, depending on the whether the voice amplification system is turned off or on. The classroom’s acoustic arrangement could be a major factor, when using voice amplification system.

A classroom may be equipped with good amplification system, but bad acoustics and the wrong placement of the speakers in the classroom may still be a hindrance to the listeners. The speaker’s connected to the voice amplification unit was mounted just above the white board, were the teacher conducts the teaching session.

According to (Pasquale Bottalico, 2018), some acoustic measures will be less sensitive to equipment and environmental variables than others, the results confirm that the acoustic parameters which were tested vary according to the acoustics of the environment. Students on

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22 both days of recording were seated primarily in the front and middle benches of the classroom, with exception to a few who were at the back of the classroom and their feedback on how they perceived the teacher’s amplified voice is reflected in the questionnaires. The increase in the SPL values on Day 2 were not too high but it was still a considerable change, when compared to Day 1 SPL values.

In Table 6, the fo of the teacher’s voice on Day 1, reduced by 1.4% from 141.5 Hz to 139.1 Hz

when the voice amplification system was turned on. Similar reduction in fo was noted on Day

2 recordings when the amplification system was on, but increased by 8.6% when the amplification was turned off in the second half of the teaching session. This could mean that the strength of the teacher’s voice was low in the first half of the teaching session, while the amplification system was used.

Then we have other factors that influence the production of teacher’s voice such as stress and attitude change. There is possibility that the vocal loading in the teacher’s voice was reduced, due to the change in the teacher’s attitude to the amplification system, such as, the teacher knew that the amplifier was working, and he didn’t have to speak louder to be heard by the students.

Research suggests that, a customized voice education that addresses individual differences in vocal behavior in a noisy environment could help the individual to adopt coping strategies based on vocal capacity and limitations, to avoid using more vocal effort than necessary to be heard in noise (Annika Szabo Portela S. G., 2018).

The whole point of using a voice amplification system is to increase the sound of the teacher’s voice without having to speak louder. The fo of a teacher’s voice changes in respect to the

amount of vocal load, discomfort and attitude being put up to deliver an audible lecture, along with proper acoustics in respect to the voice amplification system installed. So, the fo of the

teacher’s voice reduced on both days of the recordings when the amplification system was turned on and this is good for the vocal health of the teacher.

If we look into the questionnaires answered by the students, a majority of the students answered that they perceive the voice amplification system as beneficial and good. The percentage of female respondents who felt that the amplification system was beneficial was 80-100% and for men it was 64-74%. When it comes to audibility, 60-62% of female respondents and 68-79%

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of male respondents felt that the voice amplification increased the audibility in the classroom. But a majority of students were not sure if other students concentrated more with an amplification system in place. But an overwhelming majority of 84-100% of students felt that more classrooms should have voice amplification systems installed. The perception of students is important for us to know the effects of teaching patterns, attitudes towards changes in teaching, etc.

Discussion with students at the end of lectures and teaching sessions, provided significant knowledge on how to appreciate and encourage teachers to use the voice amplification system that is already in place, in some of the classrooms. The participating teacher had a positive attitude towards the amplification system and felt it was easy to handle the voice transmitter. The teacher was overwhelmingly in support of voice amplifiers installed in more classrooms in higher educational institutions.

Apart from voice amplification systems being installed, one may also consider other ergonomic factors such as air quality, reverberation properties, routine checkup for voice disorders, stress, physiological and psychological issues in teachers who use voice as a primary tool to teach their students. The employer is responsible in taking care of the work environment at workplaces and it is supported by legislation in various countries.

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24

6. CONCLUSIONS

The results of this study showed that the data collected from both days of recordings shows that the Leq [dB(C)] values from the mics around the classroom showed a considerable increase. The

middle mic on both days of the recordings seemed to receive most of the radiated effect of the amplified voice. Thus, the amplification system provides a good acoustic condition for the teacher to communicate with his students and a significant improvement in student’s comprehension of the teacher’s voice and learning conditions.

The fundamental frequency fo of the teacher’s voice decreased on both days, when the voice

amplification system was turned on. This means that with an amplifier, the teacher didn’t have to speak louder or stress too much in order to reach the students seated in different parts of the classroom. This decrease in fo of the teacher’s voice, with the amplifier in place is good for the

teacher’s vocal health such as reduce in voice disorder among teachers and a great improvement in the quality and audibility of teacher’s voice.

The responses from the students and the teacher, were overwhelmingly in support of the voice amplification system used during the recordings. Majority of the students felt that the amplification system was beneficial during the teaching sessions and would like to see more amplifiers installed in more classrooms.

The participating teacher voiced positive opinion on the handling of amplification system and felt that he was able to reach students without having to stress too much on his voice. The placement of the static microphones and the loudspeakers in the classroom also provided knowledge into where the students can hear better, depending on their seating in the classroom.

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6.1 Future studies

This study is an exploratory one, because it involved data collected from only two days of recordings. More students and a few more teachers are needed to compare how the fo of the

teacher’s voice changes in respect to the use of voice amplifiers.

This study also takes the opportunity in emphasizing the responsibilities that the higher education institutions have, in looking after their employees who primarily use voice to work.

It is not enough to see voice amplification systems installed in huge conference halls and auditoriums in higher education institutions, but every classroom, student and teacher needs it, to teach better and to be heard better.

The results of this study recommend a deeper learning into the particular voice issues that teachers have and the impact of voice amplification, with the involvement of a larger audience (more participant students and teachers), in a varied environment such as bigger lecture halls, auditoriums, etc.

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26

7. REFERENCES

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2. AKG. (n.d.). AKG DPT TETRAD NON-EU. Retrieved from

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3. Aline Duarte da Cruz, K. C. (2016 ). Evaluating effectiveness of dynamic soundfield system in the classroom. Noise & Health - A Bimonthly Inter-disciplinary International Journal, 1/13, 18(80): 42-49.

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5. America, Z. N. (2019). Retrieved from https://www.zoom-na.com/products/field-video-recording/field-recording/zoom-h4n-handy-recorder#downloads:

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6. Annika Szabo Portela, S. G. (2018). Vocal Behavior in Environmental Noise: Comparisons Between Work and Leisure Conditions in Women With Work-related Voice Disorders and Matched Controls. The Voice Foundation, 126.e36.

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http://www.gracey.co.uk/basics/leq-b1.htm

9. Bridget Shield, R. C. (2015). A survey of acoustic conditions and noise levels in secondary school classrooms in England. The Journal of the Acoustical Society of America, 187.

10. Cantor Cutiva, I. V. (2013). Voice disorders in teachers and their associations with work-related factors: A systematic review. Journal of communication disorders, 149. 11. Cantor Cutiva, I. V. (2013). Voice disorders in teachers and their associations with

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12. Carl C. Crandell, J. J. (2000). Classroom Acoustics for Children With Normal Hearing and With Hearing Impairment. Language, Speech and Hearing Services in Schools, Vol. 31, 364.

13. Carl C. Crandell, J. J. (2000). Classroom Acoustics for Children With Normal Hearing and With Hearing Impairment . Language, Speech and Hearing Services in Schools, Vol 31, 366.

14. David Pelegrin Garcia, B. S.-H. (2011). Vocal effort with changing talker-to-listener distance in different acoustic environments. Acoustical Society of America, 1981. 15. Elaine Smith, J. L. (1998). Frequency of Voice Problems Among Teachers and Other

Occupations. Journal of Voice , Page 480, Vol 12, No 4.

16. Hiroshi Sato, J. S. (2008). Evaluation of acoustical conditions for speech communication in working elementary school classrooms. Journal of the acoustical Society of America, 2075.

17. Industries, H. I. (2019). Retrieved from https://www.akg.com/dms800-system.html 18. Jana Addison, J. D. (1999). Ambient noise levels in university classrooms: Detrimental

to teaching and learning? Perpetual and Motor skills, 649.

19. Jeffery B. Larsen, A. V. (2008). The Effect of Room Acoustics and Sound- Field Amplification on Word Recognition Performance in Young Adult Listeners in Suboptimal Listening Conditions. American Journal of Audiology, Vol. 17, 58.

20. Jeffery B. Larsen, J. C. (2008). The Effect of Classroom Amplification on the Signal-to-Noise Ratio in Classrooms While Class Is in Session. Language, Speech and Hearing Services in Schools, Vol. 39, 451.

21. Lady Catherine Cantor Cutiva, I. V. (2013). Voice disorders in teachers and their associations with work-related factors: A systematic review. Journal of Communication Disorders 46, 149.

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25. Nelson Roy, R. M. (2005). Voice Disorders in the General Population: Prevalence, Risk Factors, and Occupational Impact. The American Laryngological, Rhinological and Otological Society, Inc., 1994.

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28 26. Network, O. C. (n.d.). Owners Corporation Network. Retrieved from A-weighting (dBA) and C-weighting (dBC): https://www.ocn.org.au/guide/244-weighting-dba-and-c-weighting-dbc

27. Pasquale Bottalico, J. C.-M. (2018). Reproducibility of Voice Parameters: The Effect of Room Acoustics and Microphones. Journal of Voice, 13.

28. Shield, J. E. (2012). The Impact of Sound-Field Systems on Learning and Attention in Elementary School Classrooms. Journal of Speech, Language, and Hearing Research Vol. 55, 1164.

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speech while teaching. Log Von Vocol 26, 118.

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33. Vilkman, E. (2004). Occupational Safety and Health Aspects of Voice and Speech Professions. Folia Phoniatrica et Logopaedica, 220.

34. Viveka Lyberg Åhlander, D. P. (2014). Teachers’ Voice Use in Teaching Environments: A Field Study Using Ambulatory Phonation Monitor. Journal of Voice, Vol. 28, No 6, 841.e5.

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APPENDIX A: QUESTIONNAIRE FOR STUDENTS

This questionnaire concerns students who study at higher education institutions. If you’re willing to participate, we assure you that your answers will remain anonymous. Your feedback will be held in confidence and used for the enhancement of teaching and learning in higher education institutions.

BEFORE EXPERIMENT: 1. Your gender

Male Female Other

2. Your age

18-30 31-50 51-70

3. Is your classroom equipped with amplifying system? Yes No Not sure

4. Do you have any diagnosed hearing impairment? Yes No Not sure

5. Was it hard to hear the teacher? Yes No Not sure

6. If “Yes”, do you think that using voice amplification would make a difference? Yes No May be

7. Does your teacher sound healthy? Never Sometimes Always

8. Do you perceive that your teacher’s voice causes issues such as difficulty in concentrating / hearing or anything else?

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___________________________________________________________________ ___________________________________________________________________

9. How would you rate the acoustics in the room? (e.g. carpets, curtains, noise proof windows / doors, use of amplification systems, movement of teacher around the classroom, etc.)

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AFTER EXPERIMENT:

Thank you for taking part in the experiment. We have a few more questions below and please choose your answer with a tick or X.

Did you find it beneficial to have an amplifier installed in your classroom for lecture?

Yes Not sure No

How do you perceive the amplification system?

Good Ok Bad

Did the amplified voice increase audibility?

Yes Not sure No

How would you rate your teacher’s voice?

Too low Not sure Too loud

Satisfactory Have you noted any

changes in your fellow student’s behaviour such as concentration / attention, since the use of amplifier?

Yes Not sure No

Would you like to see voice

amplification systems installed in more classrooms?

Yes May be No

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APPENDIX B: QUESTIONNAIRE FOR THE PARTICIPATING TEACHER

This questionnaire concerns teachers who teach at higher education institutions. If you’re willing to participate, we assure you that your answers will remain anonymous. Your feedback will be held in confidence and used for the enhancement of teaching and learning in higher education institutions.

BEFORE EXPERIMENT: 1. Gender

Male Female Other

2. Age

18-30 31-50 51 - 70

3. Any prior teaching experiences? Specify if any and how long. Yes No ___________________________________

4. Have you undergone teacher’s training program? Yes No

5. How many hours of teacher’s training did you undergo (approximately)?

6. Specify your level of education.

BSc MSc PhD Other ___________________________

7. How many hours do you teach every week/month (approximately)? 8.

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9. Have your students shown any sign of listening or understanding difficulties?

Yes No Not sure

10. Do you ask for your students for feedback at the end of a lecture or course? Yes No _____________________________________________

11. Do you get any feedback or comments on your voice or have shown any difficulty in hearing you while lecturing?

__________________________________________________________________

12. Do you move around while lecturing in the classroom, in order to reach students in all corners of the classroom?

Yes No Sometimes

13. Do you think that the use of amplifying system would have any impact on your teaching?

Yes No

In a positive way In a negative way

_____________________________________________________________________

14. Would you like to take part in our experiment regarding the use of amplifiers in classrooms?

Yes No

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AFTER EXPERIMENT:

1. Do you think that having an amplification system in the classroom, benefits you? Yes No May be

I used the microphone I didn’t use the microphone

2. Did you feel comfortable having to use an amplifier in the classroom? Yes No Not sure

3. From what perspective would you rate the amplifying system in your classroom? Specify if the technology works.

Positive Negative _______________________________________________

4. Do you think that students at the very end of the classroom were able to hear, understand clearly or concentrate better?

Yes No Not sure _________________________________________

5. How do you believe your amplifier benefits your students or not?

_____________________________________________________________________ _____________________________________________________________________

6. Do you think an amplification system could be beneficial to you and other teachers, if installed in all classrooms? Should the university spend on buying amplification systems for all classrooms in the campus?

Yes No Not sure

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7. Specify if you have any suggestions in regard to the use of voice amplification in teaching in higher education institutions.

_____________________________________________________________________

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APPENDIX C: QUESTIONNAIRE COMPARISON FOR STUDENTS – DAY 1 R ec or di ng s an d qu es ti on na ir es D ay 1 ( 19 th N ov em be r 20 18 ) S tu d en ts 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 W IT H O U T A M P L IF IE R G en d er F F F F F F F F M M M M M M M A g e 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 C la ss ro o m e q u ip p ed w it h a m p li fy in g s y st em ? Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es H ea ri n g i m p ai rm en t? N o N o N o N o N o t su re N o N o N o N o N o N o N o N o N o N o H ar d t o h ea r th e te ac h er ? N o N o N o N o N o N o N o N o N o N o N o N o N o N o N o If " Y es ", a m p li fi er w o u ld m ak e a d if fe re n ce ? Y es Y es D o es t ea ch er s o u n d h ea lt h y ? A lw ay s S o m et im es S o m et im es A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s S o m et im es A lw ay s S o m et im es A lw ay s A lw ay s T ea ch er 's v o ic e d if ic u lt t o c o n ce n tr at e? N o t at a ll N o N o S o m et im es N ej N o N o N o N o Y es /W o rs e N o , h e a lt h ie r w it h a m p N o N o N o R at e th e ac o u st ic s in t h e ro o m G o o d G o o d R at in g 1 0 B ra R at in g 7 M u y b ie n R at in g 9 G o o d b u t n o v e n ti la ti o n N e e d c u rt a in s/ p ro o fe d f lo o r O k S li g h t ec h o O k W IT H A M P L IF IE R W as i t b en ef ic ia l? Y es Y es Y es Y es Y es Y es Y es Y es N o t su re Y es Y es Y es Y es Y es Y es H o w d o y o u p er ce iv e am p li fi ca ti o n ? G o o d O k O k G o o d O k G o o d G o o d G o o d G o o d G o o d G o o d G o o d G o o d G o o d G o o d D id t h e am p li fi ed v o ic e in cr ea se a u d ib il it y ? Y es N o t su re N o t su re Y es N o t su re Y es Y es Y es N o t su re Y es Y es N o t su re Y es Y es Y es R at e th e te ac h er 's v o ic e S at is fa ct o ry N o t su re N o t su re S at is fa ct o ry N o t su re S at is fa ct o ry S at is fa ct o ry T o o l o w S at is fa ct o ry S at is fa ct o ry N o t su re S at is fa ct o ry S at is fa ct o ry N o t su re S at is fa ct o ry D o f el lo w s tu d en ts c o n ce n tr at e m o re n o w ? N o Y es N o t su re Y es N o t su re N o t su re Y es N o N o N o t su re Y es Y es N o t su re N o t su re N o t su re S h o u ld w e h av e am p li fi er s in m o re c la ss ro o m s? Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es Y es S tu d en ts 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 W IT H O U T A M P L IF IE R G en d er M M M M M M M M M M M M M M M A g e 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 1 8 -3 0 3 1 -5 0 C la ss ro o m e q u ip p ed w it h a m p li fy in g s y st em ? Y es Y es /N o t su re Y es Y es Y es Y es Y es Y es Y es N o t su re Y es N o t su re Y es Y es Y es H ea ri n g i m p ai rm en t? N o N o N o N o N o N o N o N o N o N o N o N o N o N o N o H ar d t o h ea r th e te ac h er ? N o N o N o N o N o t su re N o N o N o N o N o N o N o N o N o N o If " Y es ", a m p li fi er w o u ld m ak e a d if fe re n ce ? Y es Y es Y es Y es D o es t ea ch er s o u n d h ea lt h y ? A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s A lw ay s T ea ch er 's v o ic e d if ic u lt t o c o n ce n tr at e? S o m e ti m e s sl e e p y N o N o N o N o N o N ej N o N o N o N o N o /V o lu m e m a y b e R at e th e ac o u st ic s in t h e ro o m G o o d R at in g 1 0 T re s b ie n R at in g 8 G o o d H ig h s ta n d ar d B ra R at in g 9 G re at R at in g 8 G o o d W IT H A M P L IF IE R W as i t b en ef ic ia l? Y es N o Y es N o Y es N o t su re Y es Y es N o t su re Y es N o Y es N o t su re Y es H o w d o y o u p er ce iv e am p li fi ca ti o n ? G o o d G o o d O k O k G o o d G o o d O k G o o d G o o d G o o d O k G o o d G o o d G o o d D id t h e am p li fi ed v o ic e in cr ea se a u d ib il it y ? Y es Y es Y es N o Y es N o t su re N o t su re N o t su re Y es Y es Y es Y es Y es Y es R at e th e te ac h er 's v o ic e N o t su re S at is fa ct o ry S at is fa ct o ry S at is fa ct o ry S at is fa ct o ry S at is fa ct o ry N o t su re S at is fa ct o ry S at is fa ct o ry S at is fa ct o ry N o t su re S at is fa ct o ry S at is fa ct o ry S at is fa ct o ry D o f el lo w s tu d en ts c o n ce n tr at e m o re n o w ? Y es /N o t su re N o N o N o t su re N o N o N o N o t su re N o t su re Y es N o t su re Y es N o N o t su re S h o u ld w e h av e am p li fi er s in m o re c la ss ro o m s? Y es M ay b e Y es N o Y es Y es Y es Y es Y es Y es M ay b e Y es Y es Y es

The use of and attitudes to voice amplification in higher education institutions

The use of and attitudes to

voice amplification in higher

education institutions

Användning av och attityder mot

röstförstärkning i högskolor

JOSHUA DAVID ASHOK

The use of and attitudes to voice amplification in higher

education institutions

Användning av och attityder mot röstförstärkning i högskolor

Joshua David Ashok

ABSTRACT

SAMMANFATTNING

ACKNOWLEDGEMENTS

GLOSSARY / ABBREVIATIONS

CONTENTS

1. BACKGROUND

2. PURPOSE

3. METHODOLOGY

4. RESULTS

5. DISCUSSION

6. CONCLUSIONS

7. REFERENCES