Sidetone on the Orbit headset can be disabled by turning down the microphone volume level until a low double beep plays through the headset. The sidetone feature can be enabled again by turning up the microphone volume until a single beep plays through the headset. 

*The Orbit software can also be used to check the sidetone status. Side tone is enabled when the microphone volume is at 45% and above and disabled at 44% and below.*