User interfaces often incorporate sound to notify users of application updates, to enhance games, and to assist complex interactions. Sound exists as a medium that can provide information that humans cannot understand through a purely visual interaction, and in a mobile interface context, using another medium could be useful to mitigate visual limitations in screen space and the amount of users’ attention focused on screen. Smartphones are now a ubiquitous part of people’s lives, and sound interactions can play an important role within these experiences. This study conducts research on users’ interactions with supplemental sounds while using Facebook Messenger. Facebook Messenger is the most popular messaging app in the United States, and its design includes a variety of unique user interface sounds. This study contributes design considerations for both researchers and industry professionals to apply to further research or the application of audio within a mobile messaging space.