Plantronics BLACKWIRE C325-M Setup & User Manual page 11

My headset stops responding to
button presses.
For Windows Vista and Windows 7 systems
• Go to Control Panel > Sound > Recording tab.
• Highlight your device choice, select the Set Default button and
click OK.
For Mac OS X
• Choose Apple menu > System Preferences and click Sound.
• Click Output, and then select "Internal Speakers" or your device
choice.
When a PC goes into standby or hibernation, the USB headset no
longer is powered on. Be sure your PC is in an active state.
10