Cordless audio devices are widely used in the entertainment industry they include such items as professional radio microphones, cordless audio distribution, foldback and talkback systems. They also include low-cost licence-exempt consumer radio microphones, audio systems used by tour guides, and aids for disabled people.
Devices such as radio microphones are small and highly mobile. Since the professional versions tend to be moved to different parts of the world, they need to meet local regulations, and the best way to achieve this is for them to be specified at a world-wide level.