Before the Broadcast started, the organizer (myself) did a sound check. Microphone and audio were both working fine. Once the Broadcast started, all attendees could hear the presenter (myself). About 10 minutes into the webinar, all attendees lost audio. Very embarrassing since I had no indication the sound was lost. Once I figured out the attendees couldn't hear me (from all the comments in the Question pane), I did another sound check. My microphone showed many green bars and my audio check was loud. I eventually connected by telephone to continue the webinar; however, at least 10-15 minutes were lost and attendees were not happy. After 3 years using GoToWebinar, this problem occurred twice in the same week. I don't want this to happen again. Why did it happen and how could I prevent it from happening? Why would a sound check show the microphone is working but the attendees cannot hear the speaker? I'm using a desktop computer with Windows 10, Google Chrome, and high speed internet 100 mbps/10. My set-up hasn't changed in 3 years.