EXFO FTB-500 - Manual (Page 75)

Setting Up Your FTB-500
FTB-500 67
Adjusting Microphone and Speaker Volume
8. If you are using a headset and want to hear your voice through the
headphones when you speak in the microphone, from the Listen tab,
select the Listen to this device check box.
9. From the Levels tab, move the sliders until the settings are to your
liking. If the sound coming from your microphone is too low, you may
want to adjust the boost level as well.
10. Tap OK to confirm your new settings and close the window.
11. Tap OK to close the window and return to Control Panel.