Aural space is a term sometimes used by soundscape

Soundscape

A soundscape is a sound or combination of sounds that forms or arises from an immersive environment. The study of soundscape is the subject of acoustic ecology...

 designers to describe moments when listeners are hearing a space - that is, a lack of noticeable sound

Sound

Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing and of a level sufficiently strong to be heard, or the sensation stimulated in organs of hearing by such vibrations.-Propagation of...

. Quite often, there is sound present in these moments, but it is a background hum (which may or may not be deliberate on the part of the designer).

Most soundscape designers will deliberately include moments of aural space in a soundscape for a variety of reasons, such as redirecting the listener's attention, heightening tension or ensuring the listener is not overwhelmed by continuous sound.

The term "aural space" can also be used to describe moments when speakers are producing space or white noise

White noise

White noise is a random signal with a flat power spectral density. In other words, the signal contains equal power within a fixed bandwidth at any center frequency...

 - such as telephone

Telephone

The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...

 speakers during moments between connections, or when a person is on hold

Hold (telephone)

In telephony, a call may be placed on hold, in which case the connection is not terminated but no verbal communication is possible until the call is removed from hold by the same or another extension on the key telephone system. Music on hold or On Hold Messaging may be played for the caller while...

 without some kind of recording

Recording

Recording is the process of capturing data or translating information to a recording format stored on some storage medium, which is often referred to as a record or, if an auditory medium, a recording....

to fill the space.