The physical properties of sound as they pertain to a particular situation. Acoustics are often mentioned in relation to room acoustics, or how sound acts in a specific room. Acoustics is a general term describing the action of sound in a given space (it can also be the study of such sound).

A room is often said to have “good” acoustics or “poor” acoustics based on how well sound travels in and reacts to a particular environment. A “good” acoustic environment is typically one with little sound reverberation or reflection and with a flat frequency response. However, acoustics good for a home theater may be very different from those good for a cathedral (where a loud, hollow, reverberant environment may be necessary).

Generally, acoustics refers to the combination of all sound interactions within a given environment and the effect they have on sound played in the space (be it live or recorded sound).