Ordinary sounds, that is. A carrying sound, as for example elven music, might be heard by all. The residents are of all ages, both mortal and Trueblood. His tone made clear what he thought of those. Truebloods regard them with the same distaste white humans once reserved for the offspring of mixed marriages.
Some residents even have children.
We know not just what it is. I don't know why people who apply to private investigators are so often reluctant to describe the problem they want solved. He took that literally, and looked apologetic. Some mortals believe it to be something called a Bigfoot. Others, quite naturally, think it of magical origin.