These are solar sounds generated from 40 days of Michelson Doppler Imager data and processed by A. Kosovichev.

The procedure he used for generating these sounds was the following:

• He started with doppler velocity data, averaged over the solar disk, so that only modes of low angular degree (l = 0, 1, 2) remained

• Subsequent processing removed the spacecraft motion effects, instrument tuning, and some spurious points

• Then Kosovichev filtered the data at about 3 mHz to select clean sound waves (and not super-granulation and instrumental noise)

• Finally, he interpolated over the missing data and scaled the data (speeded it up a factor 42,000 to bring it into the audible human-hearing range (kHz))

Listen the Solar Sounds