It could be a memory or cache setting in your device. You have the option to turn it off with the buttons so just use those. That's not helpful. We turn sounds off so that the music/sound does not come on and disturb us/other people. If one has to turn them off every time one opens the game, it's too late to avoid…
Generally, I have my own music or an audio book in the background...so when the game sounds come blaring through, it's startling and distracting..... :)