Just making sure, did you go into Settings (in Minecraft itself), go to the Audio tab, and you did have your volume turned all the way up in the game itself? If you did, I would check your headphones/earbuds (if you are using them). I don't know if it's possible to do this but in your phone's settings, make sure that there isn't a setting to prevent an app from playing sound. If there is, it would be in an Audio/sound tab. I know that you can do that on Windows, but I have no idea about iOS. Those are my suggestions, I have no idea if it would work.
Eliza82
Just making sure, did you go into Settings (in Minecraft itself), go to the Audio tab, and you did have your volume turned all the way up in the game itself? If you did, I would check your headphones/earbuds (if you are using them). I don't know if it's possible to do this but in your phone's settings, make sure that there isn't a setting to prevent an app from playing sound. If there is, it would be in an Audio/sound tab. I know that you can do that on Windows, but I have no idea about iOS. Those are my suggestions, I have no idea if it would work.