When you stand on the rim of a canyon and yell “hello” and you hear your word a second or so later, that’s an example of echo. Essentially, it’s sound that’s reflected back to the listener. There can be multiple reflections as sound bounces off walls, floors, ceilings, and other hard objects. When these reflections arrive very close together, the listener no longer hears a distinct echo. This ten is “reverb” short for reverberation. It’s what people hear when they sing in the shower.