Use reverb to add distance to spatial audio
Reverberation
Reverberation is the phenomenon of persistence of sound after it's stopped because of multiple reflections from surfaces such as furniture, people, air, and so on in a closed space. These reflections build up with each reflection and decay gradually as they're absorbed by the surface of objects in the enclosed space.
The concept is similar to echo, but the distance between the source of the sound and also the obstacle through which it gets reflected is less with reverberation. The quantitative characterization of the reverberation is done by using the parameter called reverberation time.
SFX reverb
The SFX Reverb Effect takes the output of an Audio Mixer group and distorts it to create a custom reverb effect.
Dry level
The dry level is a mixed level of a dry signal in output in MB, and it ranges from –10000.0 to 0.0. The default is 0 MB.
Room property
The room effect level at low frequencies in MB ranges from –10000.0 to 0.0. The default is –10000.0 MB. The room effect high-frequency level in MB ranges from –10000.0 to 0.0. The default is 0.0 MB.
Decay time
Reverberation decay time at low-frequencies in seconds ranges from 0.1 to 20.0. The default is 1.0.