Please check your internet connectivity and please be aware that different devices will operate at different speeds depending on connection and coverage. 

Please try rebooting your device or at least logging off and logging back on and reconnecting via the link provided. 

For sound issues please double check you have not accidentally hit the mute button or lowered volume - you should check that you can hear other audio sources (such as a youtube video) through the device.

If you are using a tablet, please close any applications you are not using.