Computers; Earphones; Headphones; Sonars; Acoustic alarms; Acoustic amplifiers; Acoustic couplers; Alarm installations and alarms; Cables, electric; Data cables; Electric wires; Electrical plugs; Electrical sockets; Electron tubes; Encoding and decoding apparatus; Headsets for cellular or mobile phones; Personal stereos; Portable media players; Power amplifiers; Sound transmitting apparatus; Vacuum tubes for radios; Wireless headsets for smartphones; Wireless headsets for tablet computers