northern telecom as shown in fig2 the by pass cable 30 is intended to interconnect the headset 18 to the telephone system or terminal 12 such that the transmit pair 40 goes directly to the headset while the receiver pair 38 is connected to the headset via amplifier 14 in fig2 connectors 16 and 20 are shown as providing means to disconnect the headset from the amplifier and or terminal a more preferred embodiment of the by pass cable 30 is shown in fig3 in this embodiment the cable 30 including both transmit pair and receive pair has at end 32 a 4 pin modular plug 34 of the type commonly used in telephone handsets plug 34 is intended to be connected to a telephone set or terminal not shown a splitter shown generally at 36 separates cable 30 into receive pair 38 and transmit pair 40 transmit pair 40 rejoins receive pair 38 at combiner 42 the cable 30 continues on to quick connect 44 which is intended to mate with a headset not shown at splitter 36 receive pair 38 branches off to amplifier input connector 46 amplifier output connector 48 is connected to combiner 42 amplifier connectors 46 48 may also be modular handset plugs as previously described an amplifier not shown will be connected between connectors 46 48 the by pass cable thus permits the amplifier 14 fig2.