AV Is Cool Again
- By Michael Fickes
- January 1st, 2010
Remember filmstrips with an LP record providing the audio? Overhead projectors? How about those 8-millimeter films with the tinny sound tracks? Remember how boring the classroom audio-visual presentations made with that equipment were? Very uncool!
At long last, those relics of mid-20th Century educational technology have begun to disappear from many K-12 schools, which are installing very cool, new 21st Century technology.
“We estimate that about 40 percent of (K-12) classrooms today use modern multimedia audio visual (AV) projectors,” says Heather Litus Johnston, a product manager with Long Beach, Calif.-based Epson America Inc. “The trend started about five years ago when the price of these projectors fell to $1,000. Before that, only professional presenters could afford the technology. And today, the prices have fallen below $500, making them affordable for many more school districts.”
In addition to new projectors, today’s new AV technology includes interactive whiteboards and audio enhancement systems. While not new, MP3 recorders make audio files that students can easily download into their MP3 players — to review lessons or to catch up on missed classes.
All-In-One Multimedia Projectors
Full-featured multimedia projectors include DVD players, sound systems and USP connections enabling the device to project digital images from a computer PowerPoint presentation or streaming materials from the Internet.
The new gear often includes enhanced audio systems with microphone jacks connecting to speakers powerful enough to be heard at the back of the room.
A recently introduced projector includes these features along with a large format slideshow viewer that projects photos.
Long-throw multimedia projects range in cost from around $500 to $1,000. These projectors typically mount on the ceiling in the middle of the room and project images on the front walls.
For an additional $500 to $1,000, you can purchase recently introduced short-throw projectors that mount on the front wall, just above the whiteboard or projection screen. These devices project a high-resolution image over a short distance.
Short-throw projectors are particularly useful in states that regulate the way heavy equipment mounts to classroom ceilings. “In California, ceiling installations can be very expensive,” says Johnston. “Because of seismic construction and renovation regulations, a school must hire an architect to design a ceiling installation. Some structures have ceiling designs that cannot support a projector.”
For these schools, short-throw projectors that mount on the front wall are an ideal answer.
“Short throw projectors have become popular outside of California, too,” continues Johnston. “Wall mounting is always less expensive. You don’t have to run cables from the middle of the ceiling where the projector is mounted to the wall where they plug in. Here you simply run the cord down the wall and plug it in.”
The Shape of Images to Come
Look for WXGA image resolution in today’s multi-media AV gear. According to a white paper authored by Peter H. Putman, M.S., CTS, a principal with ROAM Consulting L.L.C., a Doylestown, Pa.-based classroom technology consultant, the XGA (eXtended Graphics Adapter) standard ranks as the most popular imaging format for everyday projection presentations. It features 1024 horizontal pixels and 768 vertical pixels, which creates images with 4:3 aspect ratios — the shape of most pre-HD, pre-LCD color television set pictures.
Digital television has spawned a new image shape — the shape of today’s wide screen LCD televisions. Digital television screens, as well as laptop computer screens and desktop computer monitors come in distinctly rectangular shapes, much wider than old television screens and CRT computer monitors. Modern widescreens feature 16:9 and 16:10 aspect ratios with substantially more pixels across the horizontal width of the screen and a few more along the vertical depth of the screen.
For instance, the WXGA or Wide eXtended Graphics Adapter standard raises the pixel count to 1280 pixels wide by 800 pixels deep. It forms a widescreen high-resolution image with a 16:10 aspect ratio.
Are today’s wide screen shapes easier or more difficult to watch than yesterday’s square-ish television screens? While there is little scientific research to back up the claim, film and video directors have insisted for years that wide screen images, such as the so-called letterbox images used for feature films, are more comfortable for viewers to watch and easier for them to comprehend.
Chalk blackboards ranked as the display technology of choice for, perhaps, a couple of centuries. A few years ago, whiteboards replaced blackboards. Today, low-tech whiteboards are on the way out in favor of interactive whiteboards, which can connect to multimedia projectors.
What good is an interactive whiteboard? Interactive whiteboards can connect to multimedia projectors, computers and other digital devices, such as disk drives. The instructor can draw diagrams, work out math equations or list bullet points on the whiteboard, and the projector will put a large image up on a wall so that everyone can see.
Students with laptops can tie into the whiteboard presentation and save the notes on their drive. After class, the presentation can be saved to a disk that students without laptops can access from a desktop at home after school.
According to Johnston, two school districts in the Chicago area have installed two of the new multimedia projectors in each of their classrooms. “One of the projectors connects to an interactive whiteboard, while the second projector shows the previous drawing or slide or some other reference,” Johnston says.
By combining these new tools, it becomes possible to create more comprehensive displays and more comprehensive digital files for students to review later.
Emerging classroom technology also deals with the audio side of audio-visual presentations. “It may surprise you to learn that listening activity constitutes 45 percent of the time a child spends in class each day, on average,” writes Peter H. Putman, M.S., CTS, a principal with ROAM Consulting, in a white paper entitled “Sound Reinforcement for Classrooms.”
A number of surprising studies have shown that audio reinforcement technologies improve the performance of entire classes. Putman cites a 2003 study conducted by Trost Elementary School in Oregon.
“After adding sound reinforcement to classrooms, students scored between 21 percent to 35 percent higher on standardized state literacy and skills assessment tests, and also demonstrated a 35 percent increase in fourth and fifth grade words-per-minute reading comprehension,” he writes. “In addition, Trost calculated a 72 percent decrease in teacher task redirection with voice amplification along with a 43 percent decrease in off-task student behavior.”
At the very least, then, modern classrooms need some form of amplification that enables every student to hear the teacher. “Teachers can use wireless systems with microphones that project sound through speakers,” Johnston says.
She also recommends looking into specially designed sound reinforcement systems. Putnam agrees, noting that makeshift systems don’t solve acoustical problems and sometimes create new problems. “Arrays of loudspeakers are cost effective, but are subject to the same issues with sound absorption, high-frequency roll-off and reverberation as an unamplified speaking voice — they’re just louder,” he writes.
A sound reinforcement system can be part of a projector that mounts to the ceiling. Typically, these systems employ four speakers angled down and aimed at the front, sides and back of the room. According to Putnam, such a configuration provides full room coverage and minimizes reverberations.
Lecture Capture Like College
Colleges and universities today use expensive technologies to record images of professors speaking, PowerPoint or other visual presentations being used and, of course, the professor’s voice.
While K-12 budgets probably cannot afford these systems, some colleges use systems that are affordable. The Johns Hopkins University School of Nursing uses both a high-end and low-end systems. Instructor Krysia Hudson notes that accessing recorded lecture presentations with high production values requires a laptop or desktop computer that can deal with large files.
She wants her students to have options — mobile options in particular. So in addition to high-end recordings, she makes MP3 recordings that students can upload to iPods or other MP3 players and review while on the go.
Since so many K-12 students today have their own MP3 players or iPods, an easy-to-make MP3 class recording creates an affordable make-up or review class.
Finally, these new audio-visual technologies enable teachers to play to students’ many different learning styles. Recent research indicates that different student learn in different ways. Some are visual; others learn kinetically, and are always moving around; then there are students that understand better when told something; and still others use some combination of the three. It makes sense, then, that teachers using combinations of all three will have the greatest — and coolest — success.