Incomplete question. Words in the selection are:
spacious, obscure, vestibule, unvoiced, recessed, muffled
Answer:
spacious
Explanation:
The word spacious is often used to refer to the idea a vacuum or space is empty (spacious). No wonder the author's opening words says, "We liked the house because, apart from its being old and spacious..."
Hence, we could observe that the word 'spacious' connects to the idea of emptiness.