Analogue. Some people love it, some people hate it, and some people
quest after it like it’s the panacea of sound. Personally, I love
analogue synthesizers – I love how they sound, I love how they feel,
and I love how they look.
Even among analogue synths, some filters and oscillators can sound
more organic than others. Well, ladies and gentlemen, I present to you
the most ‘organic’ oscillator on earth: the electric fish oscillator!
If you go into most pet stores, you can find a little fish called a
Gnathonemus Petersii – a member of the Mormyrid family. Most pet store
employees will recognize it as the Elephant Nose Fish.
http://www.synthgear.com/2009/audio-gear/analogue-oscillator-fish/

The interesting thing about this fascinating little animal is that
it emits pulses of electricity into the water. It uses these tiny
little shocks to locate food, other fish, and potential mates. You can
actually listen to this electric fish rather easily if if use a small
piezoelectric earphone or amplified speaker.
Here’s what you do:
Get a piezoelectric earphone here
or at Radio Shack or any electronics store. Piezoelectric earphones are
very sensitive to small electrical signals. Alternatively, you could
use a cheap computer speaker.