Place it just before a character opens the door, then follow it with a door knock for a second attempt at getting attention, or add a bell ding when the visitor is finally welcomed inside.
關於此聲音
This is a short doorbell chime lasting just over three seconds, with the familiar ring you hear at a front door. It feels instantly recognisable and a little expectant, as if someone is waiting on the other side to be let in, and its simple everyday tone carries a small jolt of attention.