The game has no sound!
The most obvious reason why your device has stopped outputting sound is that your has been turned down. To adjust the volume on your device, open the game and use the volume up/down buttons on the device’s left-hand side.
If your device is not on mute and you still have no sound please check the Ring/Silent switch located above the volume buttons. Apps will not output sound if your device is in silent mode. You can tell your mute switch is activated if it shows an orange line.
If the problem continues despite having the volume up and the Ring/Silent switch off, please try restarting your device.
For further information, please use the following Apple Support link: https://support.apple.com/HT203794