Play any or all of these videos to see & hear them together; make the browser window full-screen for the largest size videos.
This works properly on desktop or laptop browsers (mobile devices tend not to let multiple videos play at once).
Use caution with the sound, as the more videos played the louder it will be. At full-screen, the individual videos will show volume sliders for more sound control. TIP: lower the volume slider or mute the volume on a single video, then refresh the browser window and that audio setting will carry over to all the videos.