In what way does Melchor use repetition in order to create a particular mood within Chapter VI?

As the jail guards approach, the inmates throughout the jail begin to chant in low voices. They say the number two over and over again as an unknown number of prisoners is brought toward Brando's cell. When the guard arrives at the cell, he wonders aloud how all of the inmates always know exactly how many new arrivals they are bringing with them. The use of repetition in this case creates an eerie mood within the scene, building up to the moment when Brando will see that Luismi is one of the two prisoners being placed in his cell.