Lucien follows the corridors of his house, looking for Jeanne and Dawn. He could use his senses to find them faster, but he doesn't do that because he could end up listening to the girls' private conversations, and it wouldn't be good.
The girls have already said that they don't care because they have nothing to hide from him, and he doesn't have a problem with that either, but Lust insists that listening to other people's conversations can be pretty annoying and is disrespectful to those he loves.
But even without using his incredible senses, Lucien has an intuitive sense of where the girls are due to his soul contract with them. He just thinks about them, and he knows which way to go.
The house looks more lively than ever, and even though his hearing sense is contained, Lucien can hear excited voices all around, just like everyone else.