They're literally the sounds of space ringing, and they will travel out from these black holes at the speed of light as they ring down and coalesce to one spinning, quiet black hole at the end of the day.
Son, literalmente, los sonidos del espacio y saldrán de estos agujeros negros a la velocidad de la luz a medida que suenan y se funden en un agujero negro silencioso que gira al final del día.