When you straighten the line when you speak to the "plastic cover" (preferably with Instant Noodles that kind of Styrofoam
bowl, because it is easy to vibrate up) Plastic cover will be because you speak to produce sound waves impact
and vibration Plastic cover will be because you speak to produce The plastic lid will vibrate because it's hit by the sound waves generated by your words, and when the plastic lid moves, the string that's attached to the lid moves, so the other lid that's attached to the string moves, too, and the vibrations have a frequency, and the vibrations are generated by the words you say, and the various vibrations (or sound waves) that travel through the plastic lid vibrate. The various "vibrations" (or sound waves) travel through the vibrations of the plastic cover and into the air, which then hits the eardrums, and the brain processes the information coming through the eardrums, and you hear it.