The ambient sound environment. May not work when using hardware sound
the relative distance factor, compared to 1.0 meters.
The Doppler scale is a general scaling factor for how much the pitch varies due to Doppler shifting in 3D sound. Doppler is the pitch bending effect when a sound comes towards the listener or moves away from it, much like the effect you hear when a train goes past you with its horn sounding. With doppler scale, you can exaggerate or diminish the effect.
Setting this value makes the sound drop off faster or slower. The higher the value, the faster the volume will attenuate, and conversely the lower the value, the slower it will attenuate. For example, a roll-off factor of 1 will simulate the real world, whereas a value of 2 will make sounds attenuate 2 times quicker.