The built-in speakers on your computer might be playing back the sound that your built-in mic is picking up, which could cause an echo.
Also be sure to move any hand-held electronic devices (such as an iPhone) away from your mic and speakers, as this can cause feedback. If you are using a standalone microphone (i.e., not the built-in one on your computer or a headset), try moving it further away from your mouth. If possible, try using a different USB port. Try unplugging your headset or standalone microphone from the computer or device and then replugging it back in. We recommend a using USB headset plugged into your computer or headphones with a mic included plugged into you mobile device. Built-in microphones on your computer or webcam can pick up other noise and cause an echo.
See Connect to Audio using the Internet (Mic and Speakers) to learn how to select Computer audio. If you want to connect with your computer mic and speakers, then you need to make sure GoToWebinar is set to the right mode. Make sure you have Computer audio mode selected in GoToWebinar.
