Ever notice Minecraft's buttons are completely silent? Most other modern games have a subtle tick noise to simulate haptic feedback when hovering over a UI element. This mod adds that. It's a simple change but makes navigating the main menu much more satisfying.
This mod also allows configuration of the speed at which Minecraft's white border appears hovering over a button. In vanilla it is instant, but this mod allows resource pack developers to add fancy fade-in animation effects to their buttons. By default, it adds a slight dark overlay when hovering a button, which can be adjusted or disabled in the config.
Both button sounds and hover effects are configurable and able to be turned off individually. The volume and pitch of the sound is configurable, and you can override the sound file with a resource pack.