Audio APIs are sets of programming instructions that allow developers to work with sound in their applications. They provide tools to play, record, and manipulate audio, making it easier to integrate sound features into software. Common examples include Web Audio API for web applications and OpenAL for game development. These APIs enable various functionalities, such as adjusting volume, applying effects, and handling multiple audio streams. By using audio APIs, developers can create immersive experiences in games, music apps, and other multimedia software, enhancing user engagement through sound.