The pan property of the StereoPannerNode interface is an a-rate AudioParam representing the amount of panning to apply. The value can range between -1 (full left pan) and 1 (full right pan).
An a-rate AudioParam containing the panning to apply.
Note: Though the AudioParam returned is read-only, the value it represents is not.
See BaseAudioContext.createStereoPanner() for example code.