Audio frequency induction loops are used to minimize hearing problems caused by background noise in hearing aid wearers whose hearing aids are equipped with inductive sensors (induction coils). Background noise and high distance are two of the main reasons why hearing aid users are unable to hear satisfactorily in conditions that do not correspond to their immediate counterparts at rest. Induction loops are often used in churches, theatres and cinemas to help hearing-impaired people. The use of induction loop systems has also spread to communication scenarios such as ticket outlets, bank counters or drive-in/drive-through facilities. Telephones with the possibility of inductive coupling of hearing aids are another important application. This revision of the standard applies to audio frequency induction loop systems that generate an alternating magnetic field in the audible frequency range and are designed to provide an input signal for hearing aids with induction coils. Magnetic field strength requirements are established in audio frequency induction loops for hearing aids that result in sufficient signal-to-noise ratio without overdriving the hearing aid. Minimum frequency characteristic requirements for sufficient speech intelligibility are established. Furthermore, measurement procedures for the magnetic field strength are defined, statements are made about the corresponding measurement devices and the information to be made available to users of the system are specified as well as other important considerations are implemented. The responsible committee is Joint Subcommittee DKE/GUK 821.6 "Hörgeräte und audiometrische Messtechnik" ("Hearing aids and audiometric measurements") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.