The audio titled "Plastic Rattle 4" opens with the distinct sound of a plastic toy being shaken vigorously. The unique resonance of the plastic material is noticeable, providing a sample of the everyday sounds one might associate with children's toys. The shaking of the plastic toy creates a rhythmic, almost musical pattern, similar to a gentle, playful percussion instrument. As the audio progresses, the sound of the plastic rattle continues to reverberate, creating a lively and engaging auditory experience.