Which component in Unity is used for controlling sound playback?

The component used for controlling sound playback in Unity is the Audio Source. This component is essential for playing sounds in a game environment. It allows game developers to implement audio for various scenarios, such as background music, sound effects, and any other audio elements required for the gameplay experience.

The Audio Source component gives developers the ability to manage various playback options, including playing, pausing, stopping sounds, adjusting volume, pitch, and spatial settings for 3D sound placement. By attaching an Audio Source to a GameObject, the sound can be played in relation to the object's position in the game world, which is particularly important for creating immersive experiences.

In contrast, Audio Clip refers to the actual audio file that contains the sound data, but it does not control playback on its own. The Audio Mixer is used to manage and adjust multiple audio sources and their effects rather than controlling playback for individual sounds. Signal Audio is not a recognized term in Unity's audio system; instead, it may refer to concepts relating to audio input or signals in other contexts. Overall, the Audio Source is the primary component the developer interacts with to implement and control sound in a Unity project.