With the opening of the first four seals, John “heard” something and thereafter observed response. With the opening of the fifth seal, John “saw” something and then heard response. This different order helps to set off this fifth seal from the first four as having a different emphasis.
9 Quand il ouvrit le cinquième sceau, je vis sous l'autel les âmes de ceux qui avaient été immolés à cause de la parole de Dieu et à cause du témoignage qu'ils avaient rendu.