Not the loudest, but the humming of my microscope lamp, which is a circle-shaped fluorescent light. The humming came from the body of the microscope. I rested the mic on the body of the microscope and did noise reduction and amplified the audio.
Again, recorded with audacity. I did the opposite to the giant recordings, by making high pitched noises then slightly quickening the speed of the recording.
Recorded with samsung galaxy s21. You don't have to credit me anywhere but if you liked this sound effect, you can let me know in the comments where you've used it. Thanks!.