effectiveVolume

The effective gain last applied to the underlying source, folding in master, source and line volumes, occlusion, directional and distance gain.

Unlike AlSource.getVolume, this can be read from any thread without the device context. It is 0 while the source is reset or closed, so isActivated() && effectiveVolume > 0 is the actual "is this hearable right now" predicate (which canHear is not, as it only accounts for distance).

0 is silent and 1 is unattenuated; values can exceed 1 when the volume sliders are boosted past 100%.