If your GP7 audio (speaker or mic) does not work or stops working, go through the following steps until audio works. Experience has shown that GP7 audio issues are always due to one or more of the factors listed below.

• Reload GP7 in your browser. Use CTRL-R (Win/Chromebook) or CMD-R (Mac) to reload GP7 in the browser without leaving the meeting. This resolves most GP7 issues immediately.
  
• In GP7 Settings, select the correct Speaker and Mic from the respective dropdowns. (If you cannot locate your headset speaker and mic in the dropdown lists, then you are probably not using a wired USB headset, which is recommended for best results and is the only supported headset configuration. In that case, switch to a wired USB headset.)
  
• Make sure you are using the Chrome (preferred) or Firefox browser on a Win, Mac or Chromebook. Other devices and browsers can work, but are harder to use and are not supported.
  
• In the browser security, ensure that GP7 is not blocked from Mic access. This is accomplished by loading GP7 in the browser then accessing the security settings for the page using the browser's menu functions.
  
• Reboot both your router and your computer.
  
• Ensure that your computer security and privacy software is not interfering. Parental Controls software is the most common source of interfering software.
  

Source: www.pottersschool.org/gp7-audio