SELF-CONFIGURING TELEPHONE INTERFACE UNIT

摘要

A telephone interface unit automatically configures itself to couple a headset to a telephone. The interface unit comprises a switch matrix, for coupling various signal lines of the telephone to various signal lines of the headset, and a control logic, for automatically setting the switch matrix. The interface unit also comprises a variable gain circuit, for adjusting the amplitude of signals transmitted by the headset. The control logic automatically adjusts the gain of the variable gain circuit such that the gain of the headset is matched to the gain of the telephone.