What recurring sound do people hear at the home of the Manettes? What is the foreshadowing is Dickens is making with this sound? (Book 2 Chapters 1-6)

Lucy tells of her fancy that the footsteps that echo outside her house are the footsteps of people to come in and out of her life. Mr. Carton observes that this vision represents a great number of people who really will be in her life.