As pretty much all of us have been confined to working and learning from home, getting good audio during online calls and sessions has become an even higher priority. Of course, this isn’t always easy—especially when things like end-to-end network connectivity and Quality of Service (QoS) can vary greatly depending on where far-flung employees and students are located.
The equipment remote users can also vary in quality, which, of course, affects audio, noted Trent Wagner, audio products manager at QSC. “Most personal devices do not have premium quality microphones, speakers, or cameras—nor are they correctly placed,” he said. “Users will typically turn the volume up on the loudspeakers to compensate for poor levels and intelligibility, which causes a greater opportunity for echo.” He added that the acoustic echo cancellation (AEC) processing incorporated into software-based conference apps doesn’t hold up to what one can achieve with a dedicated, hardware-based digital signal processing (DSP) solution, which also contributes to an audio experience that is less than optimal.
With all of this in mind, we asked several audio experts to share how tech managers can help their remote users achieve the best quality audio possible during a time when the ability to participate in AV conferencing sessions is more important than ever. Here is their advice.
On Getting Rid of Echo
Wagner encourages remote users to eliminate the echo path between a laptop’s speakers to its microphone by wearing a headset. He said that a headset equipped with a boom microphone is best suited to this application, because it was designed with remote conferencing in mind. “These headsets often have built-in noise cancellation, which helps decrease outside distractions and increase intelligibility,” he said.
Remote users may also benefit from speakerphones that were designed specifically for remote conferencing applications. “These devices typically offer a plug-and-play interface and have advanced AEC processing and other DSP to maintain consistent levels and increase intelligibility,” Wagner said, adding that some manufacturers offer software for participants’ devices that is intended to improve the overall audio experience.
Much to tech managers’ and end users’ chagrin, network delay, packet loss, jitter, and saturated bandwidth all contribute to latent audio. “To help compensate for some of these obstacles, some companies offer algorithms that can predict, adapt to, or ‘fill in’ minor losses or adjust for jitter and reduced bandwidth in real time,” Wagner said. He also noted that some solutions apply artificial intelligence (AI) that streamlines the prediction process, thus enabling them to be more quick to adapt to network conditions.
Then, of course, there is the age-old solution (at least in terms of the internet)—what Reto Brader, CEO of Barix, describes as: “Throw bandwidth at it.” When one has more access to bandwidth, quality goes up and latency decreases.
Brader acknowledges that this isn’t always within the tech manager’s control. “For a tech manager, it is therefore important to decide which factors are most important to his or her application,” he said. Distance learning, for example, is usually less challenging because the audio signal is traveling from one person (the instructor) to the students. “For example, using an AAC+ encoder and streaming the audio to the audience using an Icecast internet radio service provides high-quality audio at low bandwidth and provides peace of mind because it [is compatible] with every browser,” he said. Panel discussions, however, are trickier, providing more of a chance for latency to occur—especially when participants are dialing in via a browser. “In panel discussions, the tech manager might opt for a solution that requires the listeners to download an app.”
On Room Acoustics
Acoustics can be a problem for remote users working and learning from home, especially if they’re living in cramped quarters. Chris Lyons, senior manager, integrated systems global marketing at Shure, counsels that when possible, users should set up shop in a space that is accommodating, acoustically. “[If you’re working in] your dining room, it might be carpeted, and [therefore] plush and quiet, or it might be the basement, which is a little more reflective and noisy,” he illustrated. “If you can, pick a spot that’s a little quieter and less reflective—more soft surfaces instead of hard surfaces.”
On Getting Down to Work
Headsets can also help to create an environment that allows users to better focus on their work, Lyons noted. “Either sound-isolating earphones that passively block out the noise, or noise cancellation built into headphones can get rid of a lot of surrounding noise, too, and you can be in your own little bubble inside of your head,” he said. “That can help a lot if you’re working at home and the dishwasher’s going, or the kids are watching TV, or there’s traffic outside, or whatever.” In a multi-function environment, where people are sharing a space that is now being used for both work and life, “suddenly environmental noise can make a big difference.”
On Giving In
Even when tech managers and users do as much as they can to achieve quality audio, there are some days when they find themselves fighting a losing battle. Again, depending on where users are located, they may experience varying degrees of network connectivity, and when it’s a bad day, this usually produces a videoconferencing call that’s out of sync or audio/video signals that simply freeze up. When faced with these issues, Lyons counsels users to turn off the video entirely, which will improve audio quality. “If I have to choose one or the other, I’ll be happy to kill the video and just rely on the audio because that’s what the meeting is really all about anyway,” he said.
More On DSP
While the shift from hardware-based codecs to soft codecs has provided users with greater flexibility, it has also raised some issues. “Soft codecs are brilliant, but at some detriment to audio,” said Nick Pemberton, director of global business development at Xilica, a DSP solutions developer headquartered in Toronto, Ontario, Canada. With a professional-grade device attached to the system, DSP can take care of echo cancellation as opposed to the software handling it, making for better audio quality. “If audio is clean and clear, and free from echoes and distortions, it’s much easier for people to spend more time communicating. If audio is bad, that’s when we see communication break down.”
Lyons argues that while professional DSP solutions may not be a cost-effective solution for home-based users right now, there is a chance that it will become a priority. “As this [work from home] trend continues, maybe we’ll go in that direction,” he said. “I could see audio [becoming] enough of a point of focus that people think: OK, if this is what I’m going to do, how do I make it so good that people don’t even know I’m at home? Right now a lot of people are assuming you’re at home, but it would be great if we could get to the point where between a video background and great audio quality, you can literally be virtually anywhere you want.”
Carolyn Heinze is a freelance writer/editor.