The impetus for this work was derived from a need to specify the alternating magnetic field at selected locations around a telephone receiver required for satisfactory inductive coupling to heating aids. It is also useful for other applications where knowledge of the magnetic field strength is required. The results, thus obtained, may be used to evaluate or specify the magnetic field strength produced by a receiver on a standardized basis. The accuracy and reproducibility of measurements made in accordance with this standard will depend primarily upon the accuracy of the test equipment used, the care with which the measurements are conducted, and the inherent stability of the telephone or transducers, or both, under test. Where a given set of measurements is repeated in the same laboratory and by the same operator, a relatively high degree of reproducibility should be obtained. When comparing measurements made by different laboratories, however, allowances should be made for the influencing factors mentioned above.