Space and Distance

AL does not define the units of measurement for distances. The application is free to use meters, inches, or parsecs. AL provides means for simulating the natural attenuation of sound according to distance, and to exagerate or reduce this effect. However, the resulting effects do not depend on the distance unit used by the application to express source and listener coordinates. AL calculations are scale invariant.

The specification assumes Euclidean calculation of distances, and mandates that if two Sources are sorted with respect to the Euclidean metric, the distance calculation used by the implementation has to preserve that order.