There’s an almost imperceptible sound you hear when you cross the threshold of a haunted house in Phasmophobia, the co-op ghost-hunting game from Kinetic Games that took Steam and Twitch by storm in the early months of the COVID-19 pandemic. As you exit your equipment truck and approach the front door, leaving the outdoor air and rain behind you, you enter a claustrophobic, dark space where a low, airy hum pervades all rooms and floors. This sound, which senior developer Ben Lavender calls “basically […] nothing,” has an outsized, unnerving effect, though when you first hear it, it’s difficult to explain why. It was one of the first details I noticed about the game, and it’s one of several finely tuned tricks Phasmophobia employs to be one of the best horror games in any era…