On YouTube, user MatdoFM has uploaded a video demonstrating what lightning sounds like over the radio and how to receive lightning pulse noise using an RTL-SDR.
When lightning strikes it releases a pulse of electromagnetic radiation, which shows up as a short wideband noise pulse over the radio spectrum. Lightning detection and mapping services like Blitzortung use a network of volunteer run VLF receivers spread out across the globe to determine the location of lightning pulses using time of arrival radio direction finding techniques.
In the video, MatdoFM uses a frequency of 124 MHz. Because the lightning pulse noise is so wideband, it extends from VLF to VHF and sometimes even UHF frequencies. At the end of his video, MatdoFM shows a lightning strike captured with his security camera and the corresponding radio sound produced by that strike.
