I had not heard the outer door open or close.

They heard the outer door to the street close behind him a moment later.

And how would you close the outer door after him?

A sound was coming from the outer door of the large office.

A moment later, he heard her close the outer door, too.

He made for the outer door but I stopped him.

He heard the outer door to the front hall open.

You will find the outer door on this side open.

Without a word, he turned and walked toward the outer door.

When it is made dark again, I will get you to an outer door.