Code of practice giving guidance on Audio-frequency induction-loop systems, Hearing aids, Electronic equipment and components, Aids for the disabled, Audiofrequencies, Marking, Graphic symbols, Symbols, Electrical equipment, Design, Circuits, Design calculations, Signal-to-noise ratio, Preamplifiers, Amplifiers, Microphones, Installation, Commissioning, Instructions for use, Maintenance, Formulae (mathematics), Receivers, Magnetic circuits, Communication cables, Electric cables,...