Connor Moore had had enough.

He uses Slack’s team communication software at his music-production company CMoore Sound in San Francisco, and the sound of notifications from the app kept interrupting his meetings. Sometimes the sound suddenly played when another user sent a message, and sometimes he heard it in the background while talking with people on Zoom video calls.

“It’s really intense,” said Moore, who has created sounds for products at Amazon, Google and Uber. He turned off the notification sound. And then he reached out to Slack. He wants to help the world sound better, he said, and he recognized an opportunity.

That’s probably a good idea, because Slack’s scratch-pop-pop-pop sound is one of the noises that people have been hearing a lot more lately.

In recent years, companies have been investing in sound to make their software and stand out. Combine that trend with increased computer usage during the pandemic, and suddenly a lot of us are noticing the sounds we used to ignore.

It’s not just Slack, which saw a wave of new users last year as the coronavirus hit U.S. shores and offices closed, causing companies to lean on virtual ways for workers to stay in touch. Microsoft’s Teams chat app chirps to notify users of new messages, while its Outlook client rings out about new emails and upcoming calendar events — and the number of meetings and emails has climbed during the pandemic, according to a study Microsoft conducted. The average Teams user is sending 45% more chat messages per week compared with the pre-Covid age.

Apple and Google’s calendar apps make sounds about events happening imminently. Apple, Discord, Facebook and Microsoft’s LinkedIn all signal the arrival of instant messages with their own custom sounds. Websites are generating their own sounds in some cases, too.

All of the noise can get to be a bit much.

“I do think the general public doesn’t have knowledge of how unhealthy constant notifications are,” said Dallas Taylor, host of Twenty Thousand Hertz, a podcast that tells the stories of distinctive sounds. “Our technology should work for us and not make us feel like we’re slaves to technology.”

Your phone doesn’t need to go off every time you get an email from a home-goods retailer that you never signed up to receive in the first place, Taylor said. Only one app on his phone is allowed to send notifications and make sounds, and that’s Slack.

The smartphone drove a sound revolution
Sound design is the process of recording or synthesizing audio to fit the needs of a moment in a creative work, such as a commercial, movie or video game. It dates at least back to the 1970s, when film editor Walter Murch was credited as a sound designer for his contributions to “Apocalypse Now.”

In the 1990s, sounds came to Microsoft Windows and the Apple Macintosh operating systems on personal computers. AOL’s Instant Messenger program made noise whenever users received new messages and friends came online.

More sounds came in the 2000s when Apple’s iPhone arrived. The smartphone emitted a sound every time a user unlocked the screen or took a photo.

That’s when the world’s largest tech companies began hiring sound designers.

Microsoft hired its first in-house sound designers, Conor O’Sullivan and Matthew Bennett, in 2009. Before that, the company had leaned on people who split sound design with other duties, such as Steve Ball, a principal program manager lead who worked on other operating system components, and product designer Benjamin Bethurum, who developed sounds such as ringtones for Windows Mobile phones and other products.

Facebook’s Will Littlejohn in his home studio.
Facebook’s Will Littlejohn in his home studio.
Facebook
Amazon’s sound-design efforts ramped up with the 2014 launch of the Alexa assistant and Echo smart speaker according to Chris Seifert, principal user experience sound designer at the company.

In 2015 O’Sullivan left Microsoft and joined Google to be its head of sound design. Google has “a handful” of sound designers today, he said.

Smaller companies’ websites have also started making sounds. Companies such as Drift and Intercom provide a means to add a chat window to the bottom of a web page where visitors can get answers to any questions they have. A widget like this will set off a chime to capture attention.

How the sounds are created
In 2014, Facebook hired Will Littlejohn, who had worked on sounds for Jawbone’s Jambox speakers and music in the Guitar Hero games, to be its sound design lead. Before that, Facebook had one sound, said Littlejohn. He and others at a firm he had co-founded came up with a series of sounds for the Messenger app, and Facebook asked if he would be willing to build the discipline of sound design at the company. Now there are more than 10 people on his team.

The team created different sounds for incoming messages on Messenger based on the device the recipient was using. Historically phones have had a limited frequency range than more powerful PCs. That’s why Facebook’s Messenger app makes a high-pitched “pop-ding” sound for an incoming message on a smartphone and a lower-pitched “pop-om” sound on a PC.

The sounds have a job to do — convey that a new Facebook message has arrived — but they’re more than just alerts. Facebook also wants them to build an association in people’s brains. If you like using Messenger and you repeatedly hear its audible elements, “you’ll carry that with you in your life as a positive part of your experience,” said Littlejohn.

Sound designers come up with their beeps and bloops using musical instruments, synthesizers, software or even with the human voice. Google and Microsoft have silent anechoic chambers on their corporate campuses that sound designers can use.

Some also record audio out in the real world.

“Almost every sound designer I know carries some type of miniature recorder no bigger than a phone, what are called field recorders,” Littlejohn said. “We record source all the time. These become things that we then can manifest in our products.”