The beautiful sounds of office life. This is audible interference from a cheap ballast in a florescent light fixture--or several in close proximity. (it's probably violating fcc regulations with rf output too. ) this was recorded with an iphone builtin mic, then processed to isolate the sound. It's a beeping / humming at around 3,800 hz. Each beep lasts about 1 second, followed by a half-second of silence before the next beep. Toward the end of this recording, it shifts slightly upward in pitch, to around 4,000 hz. Some typing on a keyboard can be heard in the foreground. (it's an office, after all. ).
Autor: Itickets