This is the sound the Project Courier time machine makes from the time it takes off from a time departure location, and while in transit through time, and until it lands in it's assigned time destination. That sound is emitted from the time interface energy field produced by the machine, which is the cobalt blue aura surrounding the exterior of the machine. That energy field also enables the machine to ascend up from a departure point, and gently descend down to an arrival location.
While traveling through time, images and sounds of; news, TV shows, events, music, commercials and such will appear inside the machine during a journey through time, sometimes with images overlapping as one image fades out and another begins. However, those images and sounds are not generated by the time machine as the buzzing sound is. Those images and sounds are simply a phenomenon of traveling through time.
During the two times Clarence traveled in the machine (once from 2018 to 1960, then from 1960 back to 2018) that buzzing sound the machine makes seemed eerie and spooky to him.
Scientists at a Horizon Innovations facility in Encino, New Mexico began planning and design of the time machine for the U.S. Air Force during the mid 1950s (code name "Project Courier"). Actual construction of the machine took place in January of 1970 at the Roswell International Air Center.
