+AMD1:2017 CSV 电声学助听器第4部分:助听器用感应回路系统系统性能要求

[中文适用范围]： 本部分 IEC 60118 适用于产生音频频率交变磁场的音频感应回路系统，旨在为带有感应拾音线圈（telecoil）的助听器提供输入信号。在本标准中，假设使用的助听器符合 IEC 60118 的所有相关部分。 本标准规定了用于助听目的的音频感应回路的磁场强度要求，这些要求将提供足够的信噪比而不会使助听器过载。标准还规定了可接受清晰度的最小频率响应要求。 规定了测量磁场强度的方法，并提供了关于适当测量设备的信息（见附录 B），应向系统操作员和用户提供的信息（见附录 C），以及其他重要考虑因素。 本标准不规定回路驱动放大器或相关麦克风或音频信号源的要求，这些在 IEC 62489-1 中处理，也不规定设备（如电话听筒）在 ITU-T P.370 范围内产生的磁场强度要求。 [外文原描述]： IEC 60118-4:2014+A1:2017 is applicable to audio-frequency induction-loop systems producing an alternating magnetic field at audio frequencies and intended to provide an input signal for hearing aids operating with an induction pick-up coil (telecoil). Throughout this standard, it is assumed that the hearing aids used with it conform to all relevant parts of IEC 60118. This standard specifies requirements for the field strength in audio-frequency induction loops for hearing aid purposes, which will give adequate signal-to-noise ratio without overloading the hearing aid. The standard also specifies the minimum frequency response requirements for acceptable intelligibility. Methods for measuring the magnetic field strength are specified, and information is given on appropriate measuring equipment (see Annex B), information that should be provided to the operator and users of the system (see Annex C), and other important considerations. This standard does not specify requirements for loop driver amplifiers or associated microphone or audio signal sources, which are dealt with in IEC 62489-1, or for the field strength produced by equipment, such as telephone handsets, within the scope of ITU-T P.370. This third edition cancels and replaces the second edition published in 2006. This edition constitutes a technical revision which includes the following significant technical changes with respect to the previous edition: Addition of Annexes G, H and I where more information is provided about practical considerations and methods of measurement. This consolidated version consists of the third edition (2012) and its amendment 1 (2017). Therefore, no need to order amendment in addition to this publication.