The Standard Model theorizes that the Higgs Field switched on about 100 picoseconds after the big bang. Recently, though, physicists have theorized that it happened a little more gradually than "switching on" in a process more like water boiling. When these bubbles of Higgs Field met, they created massive shockwaves that would have come with sonic booms. In one of the most cool theories in the early universe, the noise would have sounded a lot like thunder.
Regardless, researchers are now trying to hear the leftovers of this sonic boom.