Sound Propagation Speed

OpenAL implementations can choose to model sound propagation with limited speed for certain effects, e.g. early reflections. In addition, the Doppler Effect is defined with respect to the speed of sound in the predominant medium. The application can set the speed of sound as a scalar value. The speed is defined with respect to the scaled unit. If DISTANCE_SCALE is changed, this will affect both the distance and the propagation speed, leaving the propagation time unaffected.

A negative scale will result in an INVALID_VALUE error, the command is then ignored. The default value is 1. The current setting can be queried using GetFloatv and PROPAGATION_SPEED.