Sound can’t travel through a vacuum, but that doesn’t mean it isn’t valuable to astronomers. There’s a video at the BBC’s Science & Environment website that explains how scientists are using “the music of the stars” to study the composition of distant suns.
This isn’t the first time sound has been used to investigate the universe. A similar article from 2008 describes how this process works and why it is valuable:
The technique, called “stellar seismology”, is becoming increasingly popular among astronomers because the sounds give an indication of what is going on in the stars’ interior.
Just as seismic waves moving through Earth provide information about our planet’s insides, so sound waves travelling through a star carry information about its inner workings.
The Corot spacecraft detects the oscillations as subtle variations in the light emitted by the star as the surface wobbles. This light signal can then be converted back to sounds we understand.
Astronomers have been paying attention to planetary sounds for a long time, too, though I’m not sure what those sounds can tell us about our neighboring planets that we don’t already know thanks to other kinds of measurements. Cassini and Voyager 2 both captured the “sounds” of the spheres when passing Jupiter and Uranus; NASA posted them to a “spooky sounds” site for Halloween a couple of years back. Some of those recordings are available on Youtube, some of which sound like Lustmord or SleepResearch_Facility outtakes.
And if planets generate “sound,” then it should come as no surprise that black holes do, too.