Covert wireless earphones are essential items when it is important that the user is not seen to be using communications equipment, typically for police and military covert operations. Designed and built in the UK to medical standards, these devices give outstanding audio quality and can tolerate operating in the most hostile environments. We have recently completed the design of the VSB system which is immune from audible interference and data noise when used in areas of high AC magnetic field strength, such as in motor vehicles, on trains, and in sites with significant levels of electronic and electrical technology. All of the wireless earphones can be made as custom-fit which makes them significantly smaller as well as secure if the user has to run or engage in physical conflict. Inductive wireless earphones receive electromagnetic signals from a source such as a neck loop or an inductor pad driven from an audio source, typically from the output of a two-way radio or audio receiver.