The minimum distance, in studs, at which a 3D Sound (direct child of a BasePart or Attachment) will begin to attenuate (decrease in volume).

Sounds parented to a BasePart or Attachment that are descendants of the Workspace are considered 3D sounds and their volume whilst playing is dependent on the distance between the client’s sound listener (Camera position by default) and the Sound’s parent. Three properties influence this behavior RollOffMinDistance, Sound/RollOffMaxDistance, and Sound/RollOffMode.

The way the Sound attenuates (fades out) after the distance between the listener and the sound exceeds the RollOffMinDistance is determined by the RollOffMode.