We can't hear the sun because sound waves can't travel through the vacuum of space -- they need an atmosphere, where they travel by creating changes in pressure.
But if we could hear the sun, it would be noisy, says Scott McIntosh of the National Center for Atmospheric Research.
McIntosh and other scientists measured changes in the light waves that the sun emits and translated those changes into sound waves.
The light waves are a reflection of the giant waves of gas that travel inside the sun and burst to the sun's surface. In the picture, you can see an ejection of material from the sun in the upper right corner.
The scientists measured the light by using a dopplergraph, an instrument mounted on the Solar and Heliospheric Observatory -- one thing it can measure is the time it takes gas waves to travel through the sun. (SOHO was built in Europe under the direction of the European Space Agency and launched by NASA in 1995).
Then they used a computer model to translate the motion of the light waves into sound waves, speeding up the frequencies until the sounds were high enough to be heard by humans.
According to McIntosh, the sound of the sun includes many different frequencies mixed together. From the National Science Foundation, which supported the work:
...the multi-frequency song of the sun (is like) the ringing of cathedral bells that each hit different notes. Just as cathedral bells get louder and chime out certain pitches when certain bells are simultaneously rung, the sun belts out rhythmic bass thumps over its background hum when certain frequencies overlap with one another.
You can hear the sound of the sun for yourself here:
This post was originally published on Smartplanet.com