Compare LIGO’s chirps from black holes

The “chirps“ heard in this animation were created by converting the best-fit models of LIGO’s gravitational-wave signals into sounds. The first sound is from modeled gravitational waves detected by LIGO on Dec. 26, 2015, when two black holes merged. This is then compared to the first-ever gravitational waves detected by LIGO on Sept. 14, 2015, when two higher-mass black holes merged. The pitch of both signals is then increased, allowing them to be heard more easily. Animation credit: LIGO