In the audio titled "Slow Double Zipper," one can hear the distinct sound of a double zipper being zipped at a slow pace. The audio captures the intricacies of the sound effect, emphasizing each individual click and clack of the zipper teeth as they interconnect. It starts with a gentle tug on the zipper, followed by the steady, rhythmic progression of the zipper making its way along the track. The sound is crisp, clear, and methodical, effectively conveying the slow, deliberate movement of the double zipper.