Translation of "soundlessly" into Portuguese

Well, it sounds strange, but he went through the wall soundlessly.

Bem, soa estranho, mas ele atravessou a parede sem ruídos.

In one of the Mara’s forests, we spotted elephants, their huge gray shapes moving soundlessly between the trees.

Em uma das florestas da Mara, divisamos elefantes, suas enormes formas cinzentas movendo-se silenciosamente entre as árvores.