Help understanding compatibility between the Plantronics CT14 headset the Plantronics CT12 remote.

Although the Plantronics CT12 and Plantronics CT14 systems look alike, they do use different headsets.  The CT12 headset (part # 64378-01) has a red light on the end of the microphone that illuminates when in use (on a call), the remote unit sends an "electronic pulse" to the headset which makes this happen.  Other headsets, including the CT14 headset (part # 81083-01), will "technically" work with the CT12 system, but we only recommend using the actual CT12 replacement headset.  When using any other headset besides the original on a CT12 (including the CT14), you will more than likely hear the electronic pulsating sound fading in and out, and you could possibly also have a buzzing issue as well.