If the game is having problems playing sound, please try the following:
1️⃣ Check the game's settings to see if music and sound effects are on.
2️⃣ Restart the game.
3️⃣ Restart your device.

If the problem persists, please try the following:
1️⃣ Make sure your device isn't muted.
2️⃣ Make sure the volume is high enough.
3️⃣ Try plugging in and unplugging your earphones.
4️⃣ Make sure your music player is turned off.

If none of the above works, open another app to check if the sound is working there. If not, the problem likely has to do with your device itself rather than the game.