a low-pitched voice的用法和样例：
- Her voice dropped to a lower pitch.
- His voice dropped to a lower pitch.
- The note of the whistle is heard to change to a lower pitch.
- Talking in a low voice were a man and a woman.
- The music starts off on a low pitch, and then progresses at an evenly rolling pace.
- We talked in a low voice lest we should wake the baby up.