What does a VU meter specifically measure?

A VU meter, or Volume Unit meter, specifically measures audio levels in a sound system. It provides a visual representation of the loudness of an audio signal, which assists sound engineers and audio technicians in monitoring and adjusting sound levels to ensure they are balanced and within the appropriate range. By analyzing the peaks and average levels of audio, users can make informed decisions about mixing and mastering audio tracks to avoid distortion or clipping that can occur when levels are too high.

The other options relate to different aspects of audio-visual production. Video quality pertains to the clarity and sharpness of video images, which is assessed through different metrics and tools. Frame counts are concerned with the number of frames in a given video, important for editing and playback but unrelated to audio measurements. Color accuracy refers to the precision of color reproduction in images and video content, which also does not involve audio measurement. Thus, the main purpose of a VU meter is solely centered on assessing audio levels.