There are two possibilities for the live streaming sound not working.
1. Please make sure that your device is not on mute. Even if the media volume is turned up the application will not produce sound with the mute button on. Our application's sound does not work the same as other multimedia applications, therefore the side mute button and device sound have to be on which is different from media sound. You can also double click the home button on the device and slide to the right to make sure the mute button is not on.
This image shows the settings for the side switch on your device and the view at the bottom when you slide the device's menu up to ensure that mute is not on. REMEMBER your device may state the volume is turned up, but the mute button may still be triggered. Be sure to check the side of your device!
2. Make sure AirPlay is turned off. If you have recently connected your device to an Apple TV, other computer, or Speakers; your device may still be looking for that in order to play the audio. Therefore make sure AirPlay is set to your device.