This American National Standard provides definitions for terms used in acoustics and electroacoustics. Many terms apply to all branches of acoustics. A number of general terms from the fields of architectural acoustics, engineering acoustics, physical acoustics, physiological and psychological acoustics, sonics and ultrasonics, underwater sound, and music are also provided. Specialized terms relating to the field of vibration and shock and to the fields of psychoacoustics and bioacoustics are contained in Standards listed among the general references. Definitions provided in this Standard are intended to be consistent with their counterparts in International Standards. Terms defined in an earlier edition of this Standard for the field of recording and reproducing sound are not provided in this edition because they are more properly a subject for other Standards.