I tried to pitch my voice loud enough for him to hear me, and no more.

She pitched her voice to carry, but not too far.

She pitched her voice to be firm but not too commanding.

Trip asked, trying to pitch his voice so that only the captain could hear him clearly.

She pitched her voice low, so that only he could hear.

She pitched her voice low enough to be lost in the crowd noise.

He pitched his voice low so their mother would not hear.

Then he decides how to pitch his voice for each character.

"Right now, we have a mission to get back to," he went on, pitching his voice for the bridge at large.

He could hear the way she pitched her voice to reach him.