Conferencing Tech Sends Audio to the Forefront

New processing techniques clarify sound
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New processing techniques clarify sound
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An example of Polycom’s HDX 8000 used in a classroom setting

When it comes to designing a modern conference space, start simple.

The sheer size and functionality of today’s modern conference rooms mean that more features can be packed into different types of spaces, be it a huddle room or multifunctioning conference space. But the basics of designing a high-functioning conferencing space are just that: basics. And nowhere is that more imperative than when it comes to audio.

“Everyone wants to do a video call, but the one thing they forget is that you can’t have a video call without audio,” said Tim Droddy, regional sales manager for Revolabs, a Sudbury, Mass.-based manufacturer of audio conferencing products.

Imagine a Fortune 500 company makes a significant investment in a high-level video conferencing system without researching successful system design. Focusing on the video and leaving the audio an afterthought is typical for inexperienced clients.

“But when they don’t have adequate audio, they will understand it very quickly,” Droddy said.


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Revolabs UC1500 audio conferencing system

Rule number one: you can’t outmaneuver physics. When it comes to considering the audio components of a conferencing system, consider the physics of a room, which play a challenging role in controlling audio clarity and reverberation. It’s a reality that doesn’t apply in the same way to video.

The culprits are the glass, concrete, high ceilings and other trappings that comprise today’s modern architecture. What looks good visually can have a pervasive impact on audio in a conferencing room.

“Modern architecture means that rooms are designed with concrete and glass in ways that make it difficult for audio,” said Chris Lyons, senior manager of conferencing market communications for Niles, Ill.-based audio products manufacturer Shure.

It’s not often that building materials are evaluated when designing a conference space, unless it’s an executive conference area or designated video conferencing room. So the industry’s challenge has been to devise products that make the most of what’s in a typical room, and improve poor acoustics as much as possible. To that, there are a few design issues to consider before layout out a room.

“It’s important to understand the effect that room acoustics have on audio, especially the reverberance in the room,” said Darrin Thurston, vice president of product development for conferencing specialist Vaddio. “Reflective surfaces crate reverb. When you clap your hands in the room, and you hear that reverb back at a high level, it probably won’t be good for cancelling, and in a conferencing room it’ll turn into an event going back into the mic.”

The first solution is to reduce audio reflections, which often includes adding in acoustic wall treatments and blinds.

“No matter what advanced signal processing you’re using, you can’t overcome physics,” Thurston said.

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A conference room fitted with Shure DDX5900F microphones

Next up: location. In almost every situation, consider having a microphone as close as possible to the person who is speaking, Lyons said.

“However, because lots of rooms now are flexible-use spaces where tables get configured in different ways at different times, it’s hard to find a good audio solution that will meet all needs for a re-configured room,” he said.

Several conference solutions address this, such as the Shure DDS 5900, a gooseneck mic integrated into a base with a built-in loudspeaker. It connects via a Cat5 cable, and uses the close distance between the mic and speaker to control the sound.

“Because you’re close to both, it works equally well even if a room is loud or has A/C in the background,” Lyons said.

It’s one of those audio basics that might be overlooked, but the closer a microphone is to a speaker, the more intelligible the speaker will sound to the end user, Thurston said, pointing to the rule of thumb that says a mic should be placed no further than three to four feet from a speaker.

“That’s what you need to do if you want to optimize your speech quality,” he said.

Other solutions place a mic smack in the middle of a conference table to keep it away from A/C ducts and chatty coworkers in the hall.

“It may seem simple, but if I have a noise source in the room, I want to keep my mics as far away as possible,” Thurston said.

One such option is Vaddio’s FLX UC 1500 solution, an audio conferencing system that includes two directional microphones that can provide audio pickup in a conference room up to 18 people.

Another option sits up above. Installing a ceiling-mounted microphone array can give a larger area of coverage, said Russ Colbert with Polycom. A Polycom system has three dipole mics that offer 360 degree coverage—when the desired audio is being processed, the system uses automatic gain control to provide audio in Surround Sound with a wide frequency response.

Another key audio priority when creating a viable conferencing space is loudspeaker placement. Basic though it may be, when a company is setting up a video conferencing system, the audio should come from the same source as the video.

“It’s part of natural communication to speak to someone and look at them,” Thurston said. “So if I have audio coming from the ceiling, it’s somewhat unnatural. Participants start looking at the ceiling, and you lose that interaction with the far end.”


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A rendering of a conference space at the Smithsonian, into which a Polycom HDX 4000 system will be fitted.

Some solutions are audio-only solutions, while for others audio is no longer a standalone commodity.

That is the case for the mid-sized conference room at the Smithsonian National Museum of African Art, where educator Deborah Stokes uses a Polycom HDX 4000 conferencing system to connect with children as far away as Alaska, sharing stories about constellations, the African cosmos, science and the visual arts.

Backed by a green screen, Stokes, who is the museum’s curator for education, is able to incorporate herself into an image—much like a weatherman giving a weather forecast—to create a compelling people-on-content A/V stream that keeps students excited and engaged, she said. The Smithsonian program targets 4th through 8th grade students, as well as seniors and college students.

“The Polycom system is a great fit for my educational purposes,” Stokes said. “The people-on-content feature enables me to not only bring important objects from our museum collection directly to classrooms, but by using a green screen, I can be standing next to an object—by the pyramids in Egypt or on our National Mall in Washington D.C.”

Audio plays a vital role, too.

“I often enliven the video conference with a wide variety of video from African masquerades to the sound of stars in our cosmos,” Stokes said.

Savvy outfitters may find that the most complete solution is a converged mix of audio and video technologies.

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Vaddio AV Bridge Matrix Pro audio/video conferencing system

“In a conference room, the features and capabilities [in an A/V conference system] make it hugely different from audio conferencing [alone],” Colbert said. “Audio and video have converged so much that it becomes the way that we work together. Users can certainly adopt an audio-only solution if that’s all that they need. But phone calls are more than just a phone call—there’s calendaring and all of these other features and tools that I normally use as part of my needs in a community.”

How do you know if audio-only is the right choice? It all depends on the application, said Colbert, who is Polycom’s federal government market director.

“How big are my rooms, how many people do I have, what’s my budget, what do I need to do, what is the size of my facility?” he said. “If I’m going to try to solve global warming in Tokyo, then I need to make sure my unit has audio and video and is plugged into something other than a wall jack.”


Other companies, however, have started and stayed in audio, including Shure, which found success in the conferencing market by folding in its audio solutions with video equipment.

“Increasingly today, almost every [conferencing] room of any size has some video conferencing system in it,” Lyons said. “But most of those systems really tend to fall down on the sound quality. That’s why we try to offer systems that add on to those systems.”

To support large spaces, the new FLX UC 1500 audio-only conference solution from Revolabs can accommodate up to 18 members participating on a call. Features include two extension mics and ultra-wideband audio, up to four embedded microphones and two extension mics, and the ability to bridge VoIP and USB-based calls.

In addition, the Condor all-in-one audio system from Phoenix Audio Technologies can be positioned on top of a conferencing monitor to better address audio pickup. The Condor uses a multi-microphone array to create audio beams that target voices at distances of up to 30 feet. Features include analog, USB and optical interfaces, as well as direction finding, beamforming, echo- and noise-canceling and adaptive gain control.

Designed for huddle rooms and mid-size conference rooms, the Condor system uses a portfolio of algorithms to physically place the microphone away from a participant but still capture clear audio.

MORE INFO Phoenix Audio:





Despite the bells and whistles on both audio-only and hybrid A/V systems, challenges remain. It’s an always-changing mix to select the right number of mics, handpick between wired and wireless microphones, set up the right number of zones to eliminate unwanted noise, and process audio signals in every single call to ensure the desired acoustic level.


Hybrid A/V conferencing is also getting a boost from features like collaboration and automation.

Polycom recently introduced three new solutions as part of its RealPresence platform, which allows multiple users to connect web users to a visual collaboration network. This lets users share, view, compare and annotate multiple documents at the same time, as well as record, share, stream and play back audio and video over a web browser.

More and more users are also looking for conferencing features that allow for keeping track of tallies or recording information.

“In many cases that means we want our meetings to be screened live, or to be able to search for something you’re interested in,” said Shure’s Lyons. “That means that the audio system is part of the bigger workflow picture.”

Like much of the larger professional A/V industry, the conferencing market is also seeing a gradual merge of A/V with IP.

“Audio and video used to be a specific signal with data being a different signal,” Lyons said. “Now it’s becoming much more common for A/V to be routed over an internal network so it’s more easily distributed and more widely available.”

This poses challenges of course, not the least that you’re handing IT guys an A/V signal that they’re not familiar with, and vice versa.

One thing that’s clear: The conferencing solutions of the past—be they audio-only or a combination of audio and video—are changing based on the way business works today.

“We’re finding that the younger generations are driven by visual communications,” Thurston said. “The older generation likes phones and verbal communication, but that’s changing. It’s the visual communication, with the incorporated gestures and everything else that is engaging about multimedia, is actually a much better learning tool.”

The workplace of the future, added Colbert, needs to incorporate the future features that enable people to work and live—without having to thinking about how that audio will sound when it leaves the conference room and lands halfway across the world.