If the sounds in the game are gone, try the following:

1. Check the game settings to make sure the music and sounds are turned on.
2. Restart the game.
3. Restart your device.

This usually fixes the problem. If the sound is still missing, try this:

1. Make sure your device is not muted and that the volume is high enough.
2. Try plugging in and unplugging your headphones.
3. Make sure your music player is turned off.

If none of that worked, open another application to make sure sound is working in general. If the problem persists, it probably has to do with your device itself rather than the game.