The invention relates to a method, by which a personal communication system is formed, and a device arrangement for forming sound wirelessly to the ear. The arrangement includes an earphone part (2), a telephone part (1) and a keyboard and display device (3), between which there is a low-power radio connection. The control electronics (23) of the earphone part include a power management system, which reduces the power consumption close to zero or to zero when there is no communication between the earphone part (2) and the telephone part (1). The earphone (2) has been shaped so small that it can be fitted at least partly into the user's ear or the canal of the ear. The earphone part also includes a rechargeable or non-rechargeable battery (21) and possibly a charging system (26), which can be implemented by solar cells, kinetic energy, sound energy, induction or a thermoelectric converter. The telephone part (1) consists of a display (11), keyboard (12), one or more microphones (13), a battery (14), a radio unit (15), electronic unit (17) and an antenna unit (18). The radio technique used can be, for example, the UWB technique, which has a high data transfer capacity with low power requirement.