Improved quality commercial telephone receiver

In the past few years three factors have resulted in considerable improvements in the performance of the ordinary commercial telephone receiver. First, the replacement of voice-ear methods of testing receivers by methods which take account of their frequency response, namely, articulation tests and repetition rate tests for judging the effectiveness of a circuit or a piece of apparatus. Secondly, the introduction of the artificial ear which has made possible more exact and rapid analyses of receiver frequency response characteristics. Thirdly, new magnetic materials with considerably improved properties have recently become available. It has thus become possible to maintain the general response level of the receiver while introducing damping in order to acquire a more uniform frequency response characteristic. The paper describes a new hand-set receiver and also a new head receiver together with their construction and performance.