Loud, earth-shattering, even. Apparently the sun is a noisy place. If you want to hear an approximation of the sound, click this link. Just make sure to lower the volume on your device. The relevant part starts around 00:20.
Jillian Scudder, Forbes, asks What Does The Sun Sound Like? Scudder, a Postdoctoral Research Fellow in Astrophysics, notes that a major problem with recording sounds in space is that “there’s no atmosphere for sound waves to travel through, so any pressure waves an object may be producing will be instantly silenced without a medium to compress.” But, she adds, “there are other ways of recording information which can be translated into a sound; the easiest one is vibrations.” Enter sonification,”a booming area of data manipulation — it’s another face of the data visualization scene; instead of presenting the information visually, you can code it audibly, and listen to it over time.”
Click the link above to hear examples of sonification of the sun.