I was at Laguna Lake taking photos of the dry lake bed. Taking groups of 5 photos to combine into HDR Panorama. When I took the second set of 5, there was a very loud noise coming from my hearing aids, from one side to the other. The noise was similar to the sound of a Theremin. It startled me but I went on and took all the photos and went home. Upon looking at the completed image, there was a single disk shaped object in the image. I checked the original images and found the disk shaped object only appears in the first image of the second group of 5.