Ian Tuason’s Undertone is a true aural nightmare: unsettling, unrelenting, and downright disturbing. Yep, the film wholeheartedly delivers on its promise of being “the scariest movie you’ve ever heard,” leaning into an audio-driven approach to horror that feels both bold and unnervingly effective. But, it’s a movie that demands patience and attentiveness - asking viewers to lean in. But, trust me, the creepy payoffs it builds toward are absolutely spine-tingling. That’s not to say the film is a chore - far from it. Once the central mystery begins to take shape and the narrative threads start to tighten, Undertone locks you in with a slow, irresistible pull. The more the story unravels, the more you’ll find yourself desperate to uncover what’s lurking behind the next revelation. But be warned: as the film progresses, the discoveries become increasingly nightmarish. The horror escalates in ways that are genuinely shocking, delivering moments that stay lodged in your mind long after the credits roll. What’s most impressive is how much of this terror comes solely from sound. Tuason and his team expertly weaponize audio, turning what we imagine into something far more psychologically scarring than anything a visual jump scare could deliver. It’s a unique storytelling method, that’s for sure. Stylistically, Undertone embraces its low-fi DNA. Much like The Blair Witch Project or Paranormal Activity, the film strips away any excess and instead commits fully to a bare-bones presentation. It’s worth noting that the film’s subject matter won’t be for everyone. The horror revolves around children - babies, to be exact - which amplifies the discomfort. But, in the end, Undertone is a film you won’t easily shake. The sounds - the truly ungodly things Undertone plants in your brain - will linger long after.