So I downloaded the game about 3 days ago. I have not once heard a single sound from the game and I have checked my iPhone 6 settings, the games settings, and everything else I can think of. My phone sound is on to full, the game sounds are on at 100, and still nothing.
I hit a game breaking bug about a day into my first where I chose a kid, with a custom name, that had recently become an advlt. It locked onto that guy and I watched, in horror, as Adnan's happiness dipped to 10% and all those around him had their smiles turn to frowns. I could zoom out and in, select his SPECIAL info, and look at outfits and weapons to give him, but I could not do anything else and the camera followed him around as Vault 74 fell into indeterminable ruin.
I realized I had not updated my phone to the new iOS 8.3 so I updated, uninstalled, reinstalled, and opened up the game. After booting up the game again I have still yet to hear a single, solitary sound in game. The game seems fantastically fun from what I was able to play, but I do not want to invest too much time into a new play through just to hit another game ending bug that results in the destruction of my lovingly overseen Vault.
I don't know if anyone else has experienced any bugs such as these two, but my google and forum searches have turned up nothing so I figured it may be a novel bug worth reporting.