BiSON - Sounds of the Sun

Abstract

The Sun rings like a bell. The central frequency of the sound is far below human hearing, just 0.003 Hz. The sounds you hear as part of this work have been increased in speed by 100,000 times bringing the sound up to 300 Hz and into the range of our hearing. Of course, it is impossible to directly hear the sounds through the vacuum of space. Instead, the Birmingham Solar Oscillations Network (BiSON) at the University of Birmingham, UK, captures the data by making very precise measurements of how the oscillations cause tiny changes in the colour of the light emitted from the Sun. Measuring the oscillations allows exciting discoveries to be made about the internal structure of the Sun using a technique known as helioseismology, in the same way a geophysicist studies the Earth using seismic methods.

bison_solarsounds.flac - This file is produced from 20 years of raw solar data, captured from the beginning of 1995 to the end of 2014. Playing at 2.5 kHz produces a 100,000 times speed up and places the central oscillation frequency at 300 Hz, with a resulting audio file of just over 1 hour and 22 minutes.

bison_solarsounds_filtered.flac - This file is the same as the previous one, but it has been filtered to contain only the solar oscillation band, i.e., 2 mHz -- 5 mHz filtered with a 48 dB per octave roll-off band-pass (200 Hz -- 500 Hz after speed-up).