"Oto-" is a Greek root meaning "ear." There are several synonyms that can be used to refer to the ear, including aural, auditory, acoustical, and otic. Aural is often used to describe the perception of sound through the ear, while auditory refers to the sense of hearing as a whole. Acoustical is used to describe anything related to sound or acoustics, while otic is used specifically to describe things related to the ear. Other derivatives of the "oto-" root include otology (the study of ears and their diseases) and otoscope (an instrument used to examine the ear).