I want to create a simple grease pencil animation, but don't want to have to add sound later on, but would prefer for example an object to have sound attached, like a cloud rain and thunder. The sound should them be picked up by the camera, in stereo, depending on where the object is in relation to the camera, being louder or softer, left or right. So if the camera gets closer to the object, it the sound gets louder. I know that there was a functionality in the Blender Game Engine, which is no more as of 2.80. This is possible at all anymore?
Add a speaker object to your scene.
The speaker object has just the functionality you are after.
The speaker object is used to give sound in the 3D View. After adding the object, the various settings can be changed in the Properties editor.
Add a speaker to the scene
Add > Object > Speaker
Add sound and fill in the properties accordingly.
The speaker object can be animated as other objects.