【国外标准】 IEEE Standard Methods for Measuring Transmission Performance of Telephone Handsets and Headsets

This standard covers handsets and headsets whose receive performance can be measured using standardized artificial ears, as defined in ITUT Recommendation P.57: 1993 and ANSI S3.36-1985. The standard also covers handsets and headsets whose transmit performance can be measured with the center of the transmitter sound port in front of the artificial mouth lip plane. Othere types of handsets or headsets, having transmitters whose sound ports fall behind the lip plane in normal use, are not covered… read more by this standard. However, the general methods described in this standard may be used as guidelines for testing such handsets or headsets. This standard covers measurements on four-wire handsets and headsets having separate transmit and receive speech paths. This standard also applies to three-wire handsets and headsets in which a common lead is shared between the transmit and receive circuitry. When handsets and headsets are connected to hybrid speech networks performing four-wire to two-wire conversion, their transmission performance may be measured using the methods of IEEE Std 269-1992, with due consideration given to the relevant transmitter positioning and receiver coupling issues discussed in this standard. read less