On the Oculus documentation, they say:
Note that when Unreal PC (Rift) applications are launched, if the OculusVR plugin is enabled and the Oculus VR Runtime Service is installed, then the application will automatically override the default Windows graphics and audio devices and target the Rift. The Oculus VR Runtime Service is installed with the Oculus app.
However, with my project on Unreal Engine 4.25, I need to set my default audio source to the Oculus headset, otherwise they come through the default Windows sound device. This is true for both the editor and standalone builds.
When I upgrade my project to Unreal Engine 4.26, the default audio source automatically changes to the headset.
Unfortunately, the project is not ready for Unreal Engine 4.26 for other reasons. Is there a setting or a function call that can use on Unreal Engine 4.25.4 such that audio enters the VR headset by default, like it does on Unreal Engine 4.26 (and games that you would find on the Oculus Store)?