That's the sound of thousands of snapping or pistol shrimps snapping their claw. The noise isn't caused by the claw itself, but by a bubble formed when a tiny jet of water gets expelled from the claw at 100km/hr! The speed and low pressure turns the water into super hot  steam (4000C!), and when the bubble bursts it makes that clicking noise. At 250dB it's louder than a jet fighter! Sound courtesy of Detlef Lohse, full story here: https://www.youtube.com/watch?v=ONQlTMUYCW4 

Sounds of science: Snapping Shrimp

Untrained Tim singing in the shower

Tim performing in a house concert after his training

Look up! It's stargazing season at the ABC. Download our audio tour with astronomer Professor Fred Watson and join us on a journey across the southern night sky.

Stargazing April sky tour with Professor Fred Watson

Taylor Wilson was just 14 when he became the then-youngest person to build a nuclear fusion reactor in the world. At 22, he's a nuclear physicist with visionary ideas.

Hear the incredible saga of two nuclear boy scouts in Season 1 of Science Friction, a new show presented by Natasha Mitchell. Science, culture, and everything else in between - brought to you by ABC Science. http://www.abc.net.au/radionational/programs/sciencefriction/

This is an extended interview with Taylor Wilson from Episode 1 of Science Friction.

Radioactive obsessions: Meet the kid who built a nuclear reactor at 14 (Part 1)

Taylor Wilson was just 14 when he became the then-youngest person in the world to build a nuclear fusion reactor. At 22, he's a nuclear physicist with visionary ideas.

Hear the incredible saga of two nuclear boy scouts in Season 1 of Science Friction, a new show presented by Natasha Mitchell. Science, culture, and everything else in between - brought to you by ABC Science. http://www.abc.net.au/radionational/programs/sciencefriction/

This is an extended interview with Taylor Wilson from Episode 1 of Science Friction.

Radioactive obsessions: Meet the kid who built a nuclear reactor at 14 (Part 2)

Prof Zenobia Jacobs and Prof Bert Roberts explaining how the dates for the first humans in Australia were pushed back so far, on The Science Show with Robyn Williams.

Science Show - First Humans In Australia

A koala call, kindly supplied to RN Off Track by Brad Law from the Department of Primary Industries.

RN Off Track: Koala sounds

RN Off Track: Koala call

The recording of a south-eastern red-tailed black cockatoo fledgling preparing to fly. Supplied by Daniella Teixeira.