To fix League of Legends sound not working, check your device's audio settings and ensure the correct speakers or headphones are selected and the volume is turned up. Make sure the game is not muted or set to a low volume level in your device's volume mixer. If the issue persists, try restarting your audio device, updating audio drivers, or disabling audio enhancements. Whitelisting the game in Windows Defender or reinstalling it may also help.