To "rustle" means to make a series of quick, light sounds (such as when papers rub against each other).

This word helps you imagine that

When I had laid it on the floor

I went to blow the fire a-flame,

But something rustled on the floor,

And someone called me by my name:

It had become a glimmering girl

With apple blossom in her hair

Who called me by my name and ran

And faded through the brightening air.

-"The Song of Wandering Aengus,"

William Butler Yeats

a loud noise is heard from a distance.

a girl is speaking to the poem's writer.

something has just fallen to the ground.

something small is moving in the room.