Inside A24’s Immersive Horror: How ‘Undertone’ Redefines Audio-Driven Terror in Modern Cinema

The Pulse of ‘Undertone’: Elevating the Horror Experience with Audio Immersion

In today’s cinematic landscape, where jump-scares and eerie visuals often dominate the horror genre, A24’s latest film ‘Undertone’ carves out a rare space for stories that use sound as their true horror engine. Inspired by everything from internet creepypastas to the innocent chaos of childhood television, ‘Undertone’ isn’t just a narrative about the supernatural—it’s an experience that seeps into your ears and lives in your mind long after the credits roll.

Nina Kiri: Shouldering Solitude On-Screen

The film follows Nina Kiri in the lead role of Evy, a devoted podcast host confronted with eerie events as her personal life crumbles into isolation. While her on-screen presence is nearly singular—sharing scenes only with her silent, ailing mother—Kiri describes the process as uniquely intimate and emotionally charged. This unconventional setup created both technical and emotional hurdles. Yet, as she immersed herself in Evy’s psyche, the minimal cast and crew fostered a powerful, communal energy on set, blurring the lines between performance and reality.

Kiri’s account of the experience underlines the delicate balance required to convey fear and vulnerability without a supporting cast: ‘The cycle of energy just falls on you,’ she explains, detailing the challenge of self-generating emotional momentum in isolation. Eye contact with crew members or subtle reminders of the outside world became lifelines, anchoring her amid the character’s claustrophobic fears.

Adam DiMarco: Crafting Horror in the Void

On the other end of the audio spectrum, Adam DiMarco voices Evy’s co-host and confidant, Justin. His role is unique—almost entirely off-screen, his performance exists in the audio realm, achieved through carefully staged voice recordings. DiMarco’s sessions sometimes took place in the director’s childhood bedroom, surrounded by podcast equipment and moody lighting, helping him slip into the character’s mindset. Recording in-person interaction with Kiri added fleeting but important sparks of authenticity. Most strikingly, DiMarco relates how listening to the uncanny audio files for the first time while recording captured genuine, unfiltered reactions, strengthening the raw realism that defines ‘Undertone.’

The Power of Authentic Sound Design

Sound is king in ‘Undertone.’ The most chilling moments are triggered not by visual monsters, but by layers of unsettling, lo-fi audio. The mysterious files Evy receives—actual iPhone field recordings, as revealed by debut director Ian Tuason—carry a texture and presence that feels almost too real. ‘It feels like someone just sent it to you,’ Kiri notes, emphasizing the intimate and unsettling nature of headphone listening. These recordings expertly exploit the psychological intimacy of sound, inviting the viewer to question where fiction ends and their own paranoia begins.

The Technical DNA Behind the Terror

‘Undertone’ is a masterclass in minimalistic yet immersive filmmaking. With a tight runtime and predominantly audio-driven storytelling, the film proves that horror doesn’t need sprawling casts or splashy effects to leave a mark. Instead, it leans into current podcast culture and true crime storytelling—a trend surging across streaming platforms and podcast apps. This genre mashup brings new life to horror cinema, appealing to fans of everything from serial drama podcasts to cult genre films.

The cast list unites contemporary genre mainstays with fresh faces—including Kiri, DiMarco, Michèle Duquet, and Keana Lyn Bastidas. Helmed by Ian Tuason, the film quickly became a festival darling, collecting widespread critical praise and solid ratings for its atmospheric prowess and technical innovation. For those eager to explore an emerging wave in digital horror storytelling, ‘Undertone’ is an essential watch, best consumed alone and with headphones for maximum effect.

Innovations Worth Experiencing in Modern Horror

From its minimalistic cast to its innovative use of technology, ‘Undertone’ stands as both a love letter to and reimagining of horror’s oldest fears—the idea that what you hear in the dark can be infinitely more terrifying than what you see. In a digital age where podcasts, voice notes, and smart devices dominate daily life, the film’s commitment to authenticity and psychological immersion feels right at home, setting the bar higher for audio-first filmmaking across genres.