This standard provides techniques for objective measurement of electroacoustic and voice-switching characteristics of speakerphones that connect directly or indirectly to an analog or digital telephone network. Due to the various characteristics of speakerphones and the environments in which they operate@ not all of the test procedures in this standard are applicable to all speakerphones. Application of the test procedures to atypical speakerphones should be determined on an individual basis. Purpose The purpose of this standard is to provide practical methods for making laboratory measurements of the transmission and voice-switching characteristics of speakerphones so that their performance may be evaluated on a standardized basis.