Aural space

The space on any graph that results from a plotting of the various dimensions of sound against one another. For convenience, it usually involves plotting only two dimensions at a time. Thus, time may be plotted against frequency, frequency against amplitude or amplitude against time. Aural space is thus merely a notational convention and should not be confused with acoustic space (see this), which is an expression of the profile of a sound over the landscape. 

(Source: Schafer, R. Murray: Our Sonic Environment and the soundscape: the tuning of the world. Destiny Books 1994).