Audio
As most mobile devices have built-in speakers, it's never been easier to integrate audio into the user experience.
Mobile devices allow apps to interact with users with visual, haptic, and sound signals. It's not necessary to use all three — in fact, too many sounds can drive users away.
Sound can provide feedback or enhance the user experience when applied to strategic moments. For example, the Duolingo app uses different sounds for correct and incorrect answers and a celebratory sound at the end of each lesson.
Limit the frequency of decorative sound to reduce user fatigue. Material Design guidelines recommend avoiding using sound for:
