Slack has begun testing voice chat just a day after announcing the feature would be coming soon. Available in beta, the feature is currently only being tested on desktop in Slack's apps and in Chrome. In a statement to TechCrunch, Slack's Vice President of Product April Underwood said:
For customers who already use services like Skype, Google Hangouts, Zoom, and Bluejeans, it's easy to initiate a variety of calling features from within Slack, but for customers who need a simple solution for voice calls with members of their Slack team, this new feature will make Slack more useful. We're looking forward hearing feedback from customers testing the beta, and are eager to get this feature in the hands of customers in our Slack mobile apps soon.
As noted by TechCrunch, Slack says that the feature is currently only available to fewer than half of all users. However, if available, team administrators can check their Slack settings to enable the voice calling feature for their users.
For those with the feature enabled, you can initiate a call by clicking the phone icon at the top of a channel or a direct message thread. Whomever you initiated the call with will then be notified and you can start chatting away after they join.