Cicadas Are So Loud, Fiber Optic Cables Can ‘Hear’ Them
In 2021, scientists experimenting with fiber optics picked up a strange signal: the cacophony of cicadas. It could lead to a new way of monitoring insects.
-
WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!
Optical Cables are Microphonic
- Thread starter Berwhale
- Start date
MaxwellsEq
Major Contributor
- Joined
- Aug 18, 2020
- Messages
- 1,793
- Likes
- 2,734
I first encountered this about 20 years ago when chatting to telecoms R&D peeps. They were doing some very fine measurements of a digital protocol on a fibre loop on their campus. The noticed a signal superimposed on the digital bitstream. It wasn't high enough to result in BER, but it was there nonetheless. After checking it wasn't an error in the transmitter they concluded it was being injected, so they demodulated it and heard a pneumatic jackhammer! They found some workmen near one of the manholes.
They decided that sound causes a longitudinal change in the fibre, which affects the light carrying properties.
They decided that sound causes a longitudinal change in the fibre, which affects the light carrying properties.
Similar threads
