"Sound" according to Aristotle's De Anima (418a12) and George Berkeley's First Dialogue, is the special, or proper, object of hearing. G. J. Warnock, in his Berkeley, interprets this as meaning that sound is the "tautological accusative" of hearing: Sounds can only be heard and must be heard if anything is heard.

Hearing receives attention in philosophy mainly for its differences from seeing. Two respects in which listening and hearing differ from looking and seeing are (1) that there is nothing analogous, in seeing, to hearing the sound of something, and (2) that, in telling where something is, there is nothing analogous, in listening, to our having to look in the right direction.

Warnock's explanation of the first of these differences is that we establish the presence and existence of an object by sight and touch, and then proceed to distinguish the object thus established from its smell and taste and...