Configure sound input - Mac

Select System Preferences from the Apple menu at the top left of your screen

Click on Sound (1 in the illustration above)

Click on the "Output" tab (1). Check under the Column type (2) and locate the USB device. In our case we have a Plantronics Headset, but you may have a different brand. Click on the device to select it - the line will hilight (3).

Click on the Sound Input tab (1). Select the USB headset (2) and speak into the microphone. You should see levels indicated in (3). If nothing appears in the input level meter, check your headset is plugged in correctly and that the mute switch is not turned on if you have one. Adjust the input volume so that the level is not too high (when you speak it should be around the middle to the 3/4 mark in the level guage). Adjust the Output volume (5) to a comfortable level.