Audio duplicated

[LPGregory]

I am not sure why this is happening or if it is supposed to happen but when I make a call from an analog phone hooked to a Linksys RTP300 set up as an ATA I hear the audio duplicated over my headset attached to the computer via the mic and headphone ports. I am pretty sure this isn't supposed to be happening. It would be like tapping into the analog phone to hear a conversation that someone should not be privy to. Does anyone know why this is happening and how to correct it? The headset is for linking into the 3CX Softphone I have installed along with 3CX Assistant.