Task: Question Answering
Input (English): Context: We have a problem with our Microsoft Messenger VideoCalls : We can not transmit sound along with the video . We are using a Logitech QuickCam Pro 5000 . We used to be able to send sound though , strangely , the sound only worked via a separate microphone plugged into the mic hole in the back of the pc rather than through the microphone built - in to the Logitech camera . We had the microphone plugged into when we installed the Logitech QuckCam with the built - in microphone . 
Question: what might be the reason the Logitech mic is n't working ?
Output (English): The Logitech mic might be defective .