You know, you don’t have to wait for Halloween to watch a scary movie.

I did it last night, turning out the lights to savor George Romero’s 1968 zombie flick Night of the Living Dead on TCM.

All right, I didn’t exactly savor it. It ain’t a cinema masterpiece. In fact, much of it is pretty silly—especially the eponymous undeadsters, whose knock-kneed, reach-out-and-grasp-someone attacks and circle-eyed makeup are barely more frightening than the jocular denizens of Disneyland’s Haunted Mansion.

So why, then, do I still find this movie effective?

Well, the script’s tight, the camerawork’s claustrophobic, and the direction’s economical. But last night, I noticed a huge asset that hadn’t been clear to me before.

Its sound. Its muffled, low-tech sound.

Those hungry zombies chomping so zestfully on the purported pieces of people make a lot of subdued noise. And when they try to grab folks through the doors and the windows, you hardly hear any crashing. You do, however, hear a lot of natural-esque sound, of bumping, scratching, brushing and rustling.

And that’s what’s so effective. It’s rarely loud, with minimal (though requisite for the genre) screaming—making its impact all the more powerful. It feels real, despite the ludicrous premise and sometimes-amateurish acting. The sound makes the difference.

Few other horror movies take sound so seriously. Kwaidan is one, with its minimalist, crackling score by Toru Takemitsu. If horror these days is to remain fresh, it should take a frame out of these fearful reels. Loud smashes and bangs don’t always spark cinematic fright. But a softer, more judiciously used soundscape can—and, in turn, create an eerie atmosphere worthy of pre-Halloween watching.

In that light, I’m happy I turned up the volume on Night of the Living Dead.