-
Dimensions (mm)
6 × 12 × 2
The magnitude of the complex impedance at 1 kHz is expressed inohms. As of an impedance for a receiver, we normally offer a 150-ohm impedance, but will manufacture 300-ohm and other impedanceson demand.Input powerWhen calculating input power it is assumed the impedance isresistive, therefore, where Z is the impedance at 1 kHz in ohmsE is the input voltage in voltsE2P 103 in mW or 106 in W ZOutput Sound Pressure LevelAs a method of measuring a telephone handset, we define the outputpressure level at 1000 Hz when an earpiece is attached to theartificial ear specified in IEC318, and a voltage of 60 mV is appliedacross the receiver terminals.Please note that data comparison with those of other companies isnot valid because there are many differences in setting referencesand input conditions, although the measuring methods of othercompanies are almost similar to our method.GENERATOR EAR CAP ACOUSTIC COUPLERFrom August 16th 1991 US FCC regulations required that all telephonesin public places shall be hearing aid compatible.HAC receivers incorporate an additional coil, which produces amagnetic field that couples to the hearing aid pick-up coil.The AC magnetic field generated conforms to EIAR S-0504.Leakage Measuring EvaluationTraditionally, the performance of telephone receivers was measuredin a closed loop using the artificial ear specified in IEC 318. Thisapproach did not pose any serious problems in the past becausethere were only a few types of telephone handsets available on themarket. In recent years, however, a variety of new types of telephonessuch as cordless, portable and cellular telephones, haveentered the market one after another, and they come equipped withvarious types of handsets. In the face of these new circumferences, more and more manufactures are trying to adopt the so-calledopen measurement method, in addition to the conventional closedloop method. This is because they believe that more emphasisshould be put on auditory feeling in the working environment. Hosidenhas also decided to adopt the open measurement me