This component spawns Audio Source components along the river spline.

Such a component can be created through:

GameObject->Audio->River Audio Zone

In the screenshot above, spawning is restricted to slope angles between 15º and 90º to filter out sections that likely represent a cascade. This is a straightforward yet powerful way to position specific audio clips.

The component also linearly attenuates the volume of the created Audio Zones, based on the camera’s distance to them.