Listen Up: Breaking Classroom Sound Barriers with a Complete AV Solution

Transcription

1 : Breaking Classroom Sound Barriers with a Complete AV Solution

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3 Contents Page 4 Page 5 Page 7 Page 9 Page 12 Page 13 Page 14 Page 15 Introduction Knocking Down Student Obstacles Young Listeners and SNR English as Second Language Ear Infections Hearing Loss Learning Problems Sound Atmosphere in the Classroom Ambient Noise Reverberation and Direct Sound vs. Reflective Sound Signal to Noise Ratio Teacher Fatigue What an AV Solution Brings to the Table Control System Audio System Microphones Assisted Listening Translation to a Second Language RF Wireless Module Great Connections Reaping the Benefits of Improved Sound Better Focus; Better Learning Teachers Can Finally Hear Themselves Talk Conclusion About Chief References 3

4 Introduction Sometimes when you start a project, you need to begin with the end in mind. If you re helping to revamp an existing classroom s sound system or looking at plans for entirely new classrooms, you always have to keep the end in mind: making sure students have a positive learning experience. A fundamental yet sometimes overlooked requirement is giving students the ability to hear the message from the instructor. After all, if students can t hear what is being said, they aren t going to have the opportunity to learn to their full potential. Let s face it, classrooms can be turbulent places. Lively students, external noises from auto traffic, birds, airplanes, loud HVAC systems, computer noises, a soft-spoken teacher and students with hearing or learning problems all contribute to environments that aren t always the most conducive to learning. In addition, typical elementary students today have been raised with cell phones and the internet. Some don t even know what a chalkboard is because they use smart boards. They no longer write papers, they present them. They don t journal, they blog. 1 As someone responsible for the physical school building, your job is to help students with many distractions in their lives learn on their own terms. And that means you need to be able to capture their attention in the classroom. One way you can do this is by having AV room systems that improve sound amplification in classrooms. This white paper is designed to inform you about the barriers to adequate learning that are brought on by inadequate sound in the classroom, how an AV room system can improve sound amplification, and ultimately showcase benefits not only to students, but teachers as well. 4

5 Knocking Down Student Obstacles +15 db +9 db +3 db -3 db source-to-listener distance (SLD), ft Figure 1. Signal sound drops 6 decibels for every doubling of distance. Young Listeners and SNR Younger children have a difficult time hearing and understanding words when there is a lot of ambient noise in a room. One study reviewed the ability of 9-17 year-olds to recognize sentences in the midst of noise. The 9-year-olds performed at lower levels than the 11-year-olds, who performed more poorly than the year-olds. 2 Another study showed that children have a more difficult time differentiating signal noise from background noise, otherwise known as the Signal to Noise Ratio (SNR). Simply put, SNR is how much louder a teacher s voice is over background noise in a classroom (Figure 1). 3 If a teacher s signal is not strong enough to be heard above other noises, younger students will have difficulty hearing what s being said. English as a Second Language Another barrier younger children face is a basic ability to understand spoken English. Studies have found that children whose native language is not English require the most favorable conditions including being able to hear what is being said for language comprehension and learning. Throughout the United States, major metropolitan areas report that 20 percent or more of their school children speak languages other than English. 4 And the numbers continue to grow. Census figures indicate that while the population aged 5 and over grew by one-fourth from , the number who spoke a language other than English more than doubled. 5

6 Knocking Down Student Obstacles Ear Infections Middle ear infections create another student barrier to hearing in classrooms. These infections typically are accompanied by fluid in the middle ear that causes hearing loss. This is the most common medical diagnosis for children and some ear infections with no symptoms are untreated. Only half of all ear infections clear up within a month both treated and untreated. One estimate indicates that if there are 32 children in a first-grade class, during one school year there may be 24 bouts of ear infections that average three-to-four weeks each. Therefore, nearly every week of the school year means there will be students with some type of hearing loss from ear infections. 5 Hearing Loss Hearing loss creates yet one more obstacle to a student s ability to adequately hear what is being taught in a classroom. These days, more and more children are being diagnosed at a younger age with hearing loss, which means they head off to school with a hearing aid, cochlear implant or assisted listening device. 6 These devices make it crucial to have an SNR above +15 decibels, as recommended by the American Speech Language Hearing Association. 7 If there s too much noise in a classroom, that isn t likely to happen. One study shows that estimated classroom SNRs were -5 decibels to 10 decibels depending on the speaker. For softer-spoken teachers, this means they need to constantly use a raised voice. 8 6 Learning Problems Children with learning problems, such as attention deficit disorder or other learning disabilities, also pose another challenge because of their difficulty in understanding speech sounds in the midst of background noise. In a quiet environment, children with learning problems were able to distinguish confusing language sounds, such as ad and gab sounds. If there is excessive background noise, however, this causes excessive difficulty with the same language sounds. 9

7 Sound Atmosphere in the Classroom Ambient Noise Ambient noise in classrooms can be either internal or external. Both come from sources other than the primary instructional medium, which is typically the teacher. External noises can include airplanes, traffic, lawn mowers, playgrounds and birds. Internal noises include sounds from hallways, heating or air conditioning units, the students moving chairs or shuffling feet, computer noises and humming lights. All of these add up and ultimately compete with the teacher s voice and attention. 10 Reflected Sound Direct Sound Figure 2. A large difference between the time of arrival of the direct sound and the first reflected sound is perceived by the listener as a sense of isolation. Reverberation and Direct vs. Reflective Sound Classrooms typically are large, open rooms with fairly high ceilings and lots of smooth surfaces, which is a perfect atmosphere for creating what is commonly referred to as an echo, but more accurately is reverberation. Studies indicate that in unamplified rooms with typical reverberance and background noise, children with and without hearing problems have difficulty understanding what is being said. 11 When a person is close to us, we hear essentially direct sound including low-frequency chest tones. As the person moves farther away, we hear more of the reflected sound (Figure 2). 12 Logic dictates that the more the speaker moves away from the audience, the more difficult it s going to be for those farthest away to hear adequately. And that s exactly what happens for children sitting in the back of a classroom. 7

8 Sound Atmosphere in the Classroom Signal to Noise Ratio Stated simply, Signal to Noise Ratio (SNR) is how much louder the teacher s voice is above other sounds in the room. In essence, the teacher s voice is the signal, and all other internal and external sounds are the noises. 13 So if you think about it, a ratio higher than 1:1 means more signal than noise. Again, the SNR should be no lower than +15 decibels, which is what a child requires for intelligible comprehension Teachers Non-Teaching Professionals Figure 3. 20% of teachers have missed work due to voice problems, compared with 4% of non-teaching professionals. Teacher Fatigue In addition to the challenges students face in hearing, teachers also face a number of obstacles in being heard, which causes them to speak in a louder tone of voice and may ultimately cause strain to their vocal cords. The concern is that strain may cause temporary or permanent damage to teachers vocal cords, such as laryngitis, vocal nodules, vocal polyps and contact ulcers. 14 The Voice Academy, a virtual school for the vocal health of U.S. teachers, notes that 20 percent of teachers have missed work due to voice problems, compared with 4 percent of nonteaching professionals (Figure 3). 15 In addition to vocal strain, speaking in a louder voice is hardly soothing for the students. Generally, kids respond to raised voices as a form of reprimand. According to one study, yelling at students does not foster better behavior with students. 16 And guess what? That creates more noise, too. 8

9 What an AV Solution Brings to the Table With a complete AV room system, students and teachers ultimately experience a more optimal learning environment. The teacher s voice is amplified by a microphone and transmitted to a receiver that sends the sound to speakers strategically located throughout the classroom. Typical components include a control system, audio system, microphones and an RF wireless module. The purpose of the system is to make sure the teacher s voice or other program audio is heard clearly above background noise in the room. Let s see what one system Chief s CoPilot AV Solution offers. CoPilot AV Room System AVRW Kit Control System You need to be able to access and control your entire system in an easy manner, because the easier it is to use, the quicker teachers will adapt to it. One central system controls the power, inputs and audio, so teachers can make adjustments as needed depending on the amount of ambient noise in the classroom. This will help increase the probability that teachers will be heard by students. Also, teachers are likely to experience less vocal strain if they don t have to raise their voices. Audio System High-performance speakers that are plenum rated for the classroom are an essential part of your sound system, and that is exactly what comes with the CoPilot system. Plenum ratings ensure that nothing in open-air return ceilings is going to cause fire to spread from one section of the building to another. Standard cables are made of PVC (poly-vinyl chloride) which when burned, releases deadly chlorine gas. Plenum-rated speaker cables prevent this. 17 9

10 What an AV Solution Brings to the Table Students in the room will be able to hear clear, high-quality sound using a speaker that s integrated with a media device. The system also includes the ability to add extra speakers as the need arises. Figure 4. A lanyard-style teacher s microphone and handheld student microphone are both included with the CoPilot AV System. Having speakers that adequately amplify the teacher s voice help reach young listeners or students with learning challenges who may have trouble distinguishing certain language sounds. Also, for students with ear infections or hearing loss, this will give them the ability to more clearly hear and comprehend the information the teacher is providing. Also, increasing the SNR will aid in improving kids intelligible comprehension. Lastly, this cuts down on the amount of reverberation and thereby helps kids throughout the classroom hear especially those at the back of the room. Microphones A teacher microphone that is on a lanyard is far more comfortable than a headset. This is what s included in the CoPilot solution. Also, students need a durable handheld microphone. Both microphones should have long life that covers at least 8 hours of constant use with a rapid recharge time. Teachers need to have the mobility to move around the classroom, so the microphone should be wireless and allow mobility of at least 160 square feet (14.86 square meters). The easier it is for a teacher to use a microphone, the more likely that it will get used, thereby alleviating vocal strain. Assisted listening ear buds are another component of a good AV room system. These are particularly helpful for children with hearing losses who use hearing aids or have cochlear implants, because hearing losses reduce or eliminate many acoustical cues that are needed to discriminate between sounds. 18 So people with hearing loss must listen carefully to context, apply lip-reading skills when they can, and look for visual clues to speech content. 10

11 What an AV Solution Brings to the Table This can be tiring and difficult, especially for young children. With the amount of background noise and reverberation in classrooms, this becomes nearly impossible. Therefore, having a system that includes assisted listening ear buds like the CoPilot System is critical to the success of your system. Translation to a second language is also a helpful component of a complete room system like CoPilot. This is most beneficial for students whose second language is English (Figure 5). Figure 5. Assisted-listening ear buds can be beneficial for students with hearing loss, and for translating to a second language for ESL students. RF Wireless Module Your system should have an RF wireless module that offers networking via control and video components. The system should offer Mica/IR pairing to any room and any campus. Typically, there are two types of wireless transmission used in sound amplification. Radio frequency (RF) employs electromagnetic radio waves to carry a signal. Most classroom systems currently use IR (infrared) technology for their AV room systems. CoPilot uses RF, which offers many benefits in a classroom setting: IR System Easier use for teachers because line of site between the microphone and base unit is not necessary (Figure 6). RF is faster than IR, with RF products able to receive and process hundreds of responses per second. RF System RF range is greater than IR. The CoPilot RF system has a 40-foot plus open field range from the microphones to the base unit. Figure 6. IR requires line-of-sight, which can cause disruption if the teacher turns away from the base unit. Line-of-sight is not necessary with RF systems. You can have up to 25 units in an overlapping space without any signal problems. IR signals are prone to interference with fluorescent lights and natural light, which most classrooms have. RF has no problem with either. 11

12 Sound Atmosphere in the Classroom Your sound system should also be easy to use and support an infinite number of classroom installations on the same campus. Great Connections A complete AV solution such as the CoPilot system will give you the flexibility to connect: A projector screen to a system that automatically raises and lowers the screen based on whether the projector is turned on or off Up to two computers To a DVD or VCR To an external auxiliary audio input such as an ipod for background music To the fire alarm, security system and lockdown system 12

13 Reaping the Benefits of Improved Sound No Audio Enhancement Year 1 Year 2 Year 3 By applying logic to the conundrum of poor sound in a classroom, it only stands to reason that students who can t hear what is being said are going to lag behind academically. A number of studies indicate that better sound in classrooms leads to higher student achievement, better attentiveness and higher teacher satisfaction levels SAT scores in reading, math and science Figure 7. School trials of audioenhanced classrooms improved achievement scores with urban, high-need students. Here are some indicators that improving sound in classrooms has a direct impact on student achievement: School trials of audio-enhanced classrooms improved achievement scores with urban, high-need students. As a result of installing an audio enhancement system in 5th grade classrooms, Stanford Achievement Test (SAT) scores improved in reading, math and science from 10 percent to 15 percent. In the second and third years of the audio enhancements, test scores improved 10 percent a year for both years (Figure 7). 19 A three-year study of middle school students gains who were taught in sound-enhanced classrooms showed significantly improved student achievement among 6th, 7th and 8th grade students. The study showed a minimum gain of 11 percent on the Florida Comprehensive Assessment Test (FCAT). 20 A minimum 10 percent gain per year in student achievement was recorded after sound enhancement equipment was installed in intermediate school classrooms outside of Detroit, MI. 21 Reading, math, language arts and spelling showed gains of 15 percent over multiple years for 3rd and 4th grade students in classrooms with enhanced audio

14 Reaping the Benefits of Improved Sound A Florida middle school that uses a comprehensive audio enhancement system that includes built-in amplification for teachers voices in each classroom has seen a 10 percent gain in achievement test scores in the first year of audio enhancement Non-amplified Classroom Amplified Classroom English language learners who were taught in classrooms with audio enhancements showed test scores with an average improvement of 16 percent on SAT and Utah s Criterion Reference Test scores. 24 Dyslexic children scored between 44 percent and 48 percent on reading tests before classrooms were amplified. After the classrooms were amplified for seven months, the score improved to 75 percent (Figure 8). 25 Better Focus; Better Learning Better on-task student behavior testing has also been conducted in several schools with the following results: Figure 8. Dyslexic children scored 27 31% better on reading tests after seven months in an amplified classroom. Classrooms that used sound enhancement systems indicated consistency in the decline of off-task behavior for all classes that used the system over classrooms that did not. 26 Children exposed to ambient noise experienced increased stress and physical health concerns. If students cannot focus on what the teacher is saying, they not only lose the desire but also the ability to learn. 27 Students in amplified elementary school classrooms showed an average 17 percent increase in their overall on-task behavior

15 Reaping the Benefits of Improved Sound Teachers Can Finally Hear Themselves Talk In addition to better achievement and more on-task behavior from students, teachers also benefit from enhanced sound systems in classrooms in the following ways: Research indicates that the use of classroom amplification is conducive to teachers more efficiently using their voices. Ultimately, this means reduced vocal fatigue. 29 Teachers support the use of a sound field system because they can move around the classroom and do not have to repeat instructions as often. 30 The use of a wireless microphone by the teacher and loudspeakers placed in the room improved classroom management and decreased teacher vocal fatigue. 31 Iowa teachers who used a sound field classroom amplification system had a 36 percent decline in absenteeism when compared to teachers not using the same system. Complaints and sick leave for voice, jaw or throat problems decreased dramatically for teachers who used a sound amplification system. The data showed that using sound amplification systems would result in substantial savings for the school district in substitute teacher pay. 32 Teachers in southern New Jersey were asked how a sound amplification system helped them and 50 percent responded that they felt less fatigued and stressed. 33 Research suggests that improving school facilities, including better classroom acoustics, may lead to higher teacher retention rates

16 Conclusion Adequately amplifying the sound from the teacher to the student in classrooms can improve student achievement, get students to better focus and help relieve vocal and other stress for teachers. When it s time to make a selection for an AV room system, you not only have to look at the technology but also at the needs of your students. After all, what you re trying to accomplish involves making the educational environment as conducive to learning as possible. Take a look at the CoPilot AV Solution, which brings you technology that s engineered for simple operation for users with all levels of technical ability. The intuitive nature of the product gives teachers a centralized source for operating the system. All told, students are better able to hear what is being taught, thereby improving achievement and satisfaction with the learning environment. For more information about Chief s CoPilot AV Solution, visit 16

17 About Chief Manufacturing Chief Manufacturing is a division of Milestone AV Technologies, a Duchossois Group Company. With over 30 years of proven product and service excellence, many product awards and patented designs, we are globally recognized as a leader in the audio visual industry. We design state-of-the-art mount, rack and AV solutions that complement the technology they support. We are committed to delivering high-quality products that are easy to install and maintain. To learn more, visit our website at You can also on Twitter or become a fan of Chief on Facebook for the most up-to-date information. 17

18 About Chief Manufacturing Chief Contact Information Chief Manufacturing 8401 Eagle Creek Parkway Savage, MN 55378, USA Derek Derks Product Manager - CoPilot Karen Mefford Karen.Mefford@Milestone.com Marketing Manager - ProAV 18

19 References 1 Motivation and Learning in the 21st Century (video), L Nicole Fox, K-5 technology teacher, Linwood Elementary, Wichita, KA. 2 Classroom Acoustics II, Acoustical Barriers to Learning, Technical Committee on Speech Communication of the Acoustical Society of America, The Institute for Enhanced Classroom Hearing, 4 Language Use and English-Speaking Ability, Census 2000 Brief; The Hearing Journal, Vol. 61, Issue 2, February Facts about Hearing Loss in Children, 7 Acoustical Society of American 139th Lay Language Papers, Acoustical Society of American 139th Lay Language Papers, Classroom Acoustics II, Acoustical Barriers to Learning, Technical Committee on Speech Communication of the Acoustical Society of America, The Institute for Enhanced Classroom Hearing, 11 The Institute for Enhanced Classroom Hearing, 12 Film Sound Web Site, 19

20 13 The Institute for Enhanced Classroom Hearing, 14 Teachers who overuse voices may experience vocal cord problems, Crescent News, news/article/ ,oct. 2, Teachers who overuse voices may experience vocal cord problems, Crescent News, news/article/ ,oct. 2, Stop yelling, it doesn t help, Education News, html,caroline Milburn, Oct. 25, Assistive Listening Systems Technical Bulletin, June 1, McCarty, CEFPI Paper Presentation, 2003 and BYU Department of Human Development study, BYU Study, Bernier, Odyssey Middle School, Orange County Public Schools, Florida, Oakland ISD Sound Enhancement Report, Deborah Edwards, Office of Student Services, Oakland Intermediate Schools, Boggs & McClanahan, Anaheim Public Schools, California, Clark, Orange County Public Schools, Florida, McCarty, CEFPI Paper Presentation, 2003 and BYU Department of Human Development study, Utah Public Schools, Utah Elementary Schools Principals Association Conference, February Ryan, University of West Florida,

21 27 Evans, Cornell University, Allen, Dubuque Iowa Public Schools, Johnson, University of Northern Iowa, Osborn, Putnam County Educational Service Center, Palmer, University of Pittsburg, Allen, Dubuque Iowa Public Schools, Classroom Acoustics and the Benefits of Sound Field Amplification, April 5, Buckley, Boston College, Milestone AV Technologies, a Duchossois Group Company A 5/10. Chief is a registered trademark of Milestone AV Technologies. All other brand names or marks are used for identification purposes and are trademarks of their respective owners. 21

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