The term 'Device Causing a Musical Echo' can be summarized as 'REVERB' (6 letters). REVERB is an effect used in music production that creates an echo-like sound. It is created by reflecting sound waves off of surfaces, such as walls or ceilings, and then recording the reflections. REVERB is used to create a sense of space and depth in a recording, and can also be used to add texture and atmosphere to a track.