There are a slew of audio-only games available for iOS (I’ve covered Papa Sangre, and Nightjar previously). The two newest are called Vanished and Blindside. In the case of Papa Sangre, it’s fitting to post this again on Hallowe’en. They’re pretty intense to play.
Calrec’s community site has given a nice overview of Vanished and shows the interest that I share in using sound-based storylines in games. Download one of them and enjoy the thrill of sonic terror.