Just as light has a physicality to it and has mass, so does sound, and extends as far as its energy can take it.
The artist James Turrell (who creates volumes of light) used to talk about the "thingness of light". The simple analogy in sound is the feel of bass, that might not have a defined pitch, but propagates and travels through materials instead of reflecting off of them, and extends out of the spaces in which they are produced.
Sounds can define places as well: The outer isobels can define the circumference of a town and/or tribal boundaries. In medieval times, The town limits are where the church bells begin to be audible with normal hearing.