Discord launches noise suppression for its mobile app

Voice, video, and text communication service Discord is launching noise suppression for mobile audio calls. That means no one will notice if you’re taking a walk in a windy park during a meeting — or making noises in the toilet.

Based on the publicly available Krisp machine-learning-based audio filtering technology, Discord’s app will now filter out noise. The machine learning algorithm looks for sounds that are common background noises in calls and then stops them from being passed on to the audio compression technology, which in turned is based on the Opus audio codec. Discord’s platform depends on both Krisp and Opus to provide high-quality audio for more than 100 million monthly active users, who also use the platform’s video and text chat features.

Krisp can filter out leaf blowers, wind, car horns, and the ever-embarrassing toilet flush sounds, said Discord chief technology officer Stan Vishnevskiy, in an interview with GamesBeat.

“Our whole mission is around being your place to talk, and so this was about how we take it to the next level and make sure you can do that anywhere without noise interference,” he said. “You can use it outside or inside. We brought it into the desktop app a couple of months ago and it has been quite popular.”

Discord partnered with Krisp.ai to bring noise suppression to the Discord desktop app in April, and now it is getting around to the mobile version on iOS and Android. But Vishnevskiy said the company had to be careful, making sure the tech works without consuming too much CPU usage. Audio chat can only take up a small amount of the processing power, as people often multitask with games or other apps while they’re engaged in voice chat. Discord said that its voice channel takes up about 1% to 2% of CPU performance on a desktop. With Krisp, it may consume 3% to 4% on the same device. For mobile, the range of CPU usage is 6% to 15% CPU for Discord voice channels on Android devices, without any noticeable increase when Krisp is turned on.

Noise suppression has become increasingly important because, during the pandemic, we’re always getting on audio calls where we can’t control the environment around us. Krisp filters out the noise interference, whether it comes from children, gardeners, wind, keyboard typing, construction, or toilet sounds.

I got a feel for this problem the other day when playing Call of Duty: Warzone with three other human players. I was using my gaming laptop, and the other guys complained at how much noise they heard. I didn’t know what it was until I realized they could hear my laptop’s fan, as it was struggling to drive the heat from the graphics processor out of the machine. I was using the in-game chat, and it didn’t filter out the fan noise at all.

Vishnevskiy said Discord’s noise suppression is liberating because now you can take a walk or hang out in a noisy place while you’re taking business calls. It filters out anything that isn’t a human voice. You can microwave popcorn, let your kid enjoy their harmonica, or give your dog that new squeaky toy you know they deserve. No one on the other end will hear a peep, the company said.

When you are connected to a voice channel, you can enable the sound wave icon to filter out background noise.

“Audio and video are like a big part of people’s lives right now, and more people are in crowded rooms and environments,” Vishnevskiy said. “We worked with Krisp to make sure we could bring it to everyone on all our platforms, so it doesn’t matter where you are — you could have the best possible conversation.”

Discord recently raised $100 million on a valuation of $3.5 billion. The company recently said it has expanded beyond games to address all kinds of communications needs.