Dynamic compression is the process by which a processor or VST reduces the difference between the highest peaks and the quietest moments of an audio signal. In radio, it's strictly used to match the voiceover talent with the background music bed, ensuring the message maintains a solid, impactful presence and doesn't get lost when played on small speakers or in noisy environments.

This technique is crucial in commercial radio spot mastering. By reducing the dynamic range, we achieve a more consistent loudness level. This means the announcer's voice stays front and center, clear and intelligible, even when competing with music or background noise. It guarantees the ad cuts through the clutter and delivers its message effectively across various listening scenarios.