- When a sound is reflected off a surface, such as a wall, and heard by the original source.
- When a sound is reflected off an object, such as a tree, and heard by the original source.
- When a sound is reflected off a surface, such as a canyon wall, and heard by a listener.
- When a sound is reflected off a surface, such as a body of water, and heard by the original source.
- When a sound is reflected off an object, such as a building, and heard by another listener.