The feature will be limited to the iPhone 8 and later, iPad Pro 12.9-inch (second generation) and later, iPad Air third generation, iPad Mini 5th generation and iPod Touch seventh generation (via 9to5Mac).
In addition, the feature will only work with certain headphone models. Obviously these include the 1st-gen AirPods and 2nd-gen AirPods, and the Beats Powerbeats Pro. But it's unclear if third-party Bluetooth headphones will be compatible.
Apple's iOS 13 preview (opens in new tab) page only mentions AirPods and neither the PowerBeats Pro or third-party headphones. So it's anyone's guess. We've contacted Apple for clarification and will update this story if we hear back.
Apple announced iOS 13 earlier this month. The operating system is currently only available to developers, but a public beta will launch next month ahead of the consumer release in September.