he cost. OEMs need to recognise at the design stage that the headset is the all important man-machine European standards for telephones are country specific and contain interface, and although an accessory to the system, its performance many national peculiarities, which prevent the production of a is a critical aspect of the total system design. The recently intro- single harmonised telephone suitable for use anywhere in Europe. duced range of quality headsets, such as Profile, are of advanced NET 4 (Norme European de Telecommunication) for basic PSTN design and construction and offer exceptional performance. They access was produced under an EEC directive in 1986 and covers all use the latest surface mount technology and because of their micro- the essential parameters of signalling, transmission and safety. A miniature design, and the need for customisation to a wide range of new EEC directive in 1991 established the concept of CTRs (Com- PABX, ACD, Key Systems and other telephone instruments, are mon Technical Regulations) which will supersede the NETs with generally hand-assembled. The flex cord, too, needs to be of high the aim of establishing the essential requirements to be regulated. quality to ensure reliability and, in some cases, is tested to withstand The harmonised standards give the specifications and tests to be 750000 test flexures. applied to ensure conformity with the requirements. The CTRs will Compared with a handset, the headset has to be light yet able to not duplicate other requirements already in existence, such as the withstand hard use. It is constantly picked up and frequently LVD (Low Voltage Directive). The objective is, some time in the dropped and tends to be under constant flexure. future, to be able to test and approve telephones in one country in Developments in modern plastics, and the introduction of the Europe, apply the EC Mark, and sell that telephone in any other electret microphone have allowed development of headsets weigh- country without further approval testing. At pr