Hi Carlos_Rosario_Silva, I understand that when you make Facebook video calls that the receiving person does not hear audio. After doing some research on the Facebook Video site, it look like they have some posted troubleshooting tips for audio issues: [https://www.facebook.com/help/325947034156919/] Also check to make sure you have properly shared your microphone: [https://www.facebook.com/help/325947034156919/] Please try those first. Then in your Firefox there are two places for checking the status of sharing your microphone. # In the call window, right click and select "Page Info". # Click on the permissions tab and scroll down to the microphone. Please make sure that this is given permission to share In order for the receiver to troubleshoot the call audio, please also ask them to make sure that it is only the audio in a call from you and not others as well.