The Bulgarian mental health technology company has released the largest update in its 6th Mind app’s history, adding a headset mode that turns the phone’s screen into a full-field light stimulation source, eyes-open sessions, themed session bundles, and a browser-based session library.
Sofia, Bulgaria – 6th Technology, a mental health technology company based in Sofia, Bulgaria, has released version 2 of 6th Mind, its audio-visual entrainment app for iOS and Android. The update introduces a headset mode that uses the phone’s screen as a full-field light source, sessions that can be completed with open eyes, themed session bundles called Mental 6-packs, an expandable daily routine, and a web-based Session Library. The app remains available at no cost, with no advertising.
6th Mind version 2: headset mode, Mental 6-packs and the Session Library.
Audio-visual entrainment, or AVE, combines rhythmic light and sound to guide the brain’s electrical activity toward a target frequency: slower rhythms associated with relaxation and sleep, faster ones with focus and alertness. Dedicated AVE devices typically sell for several hundred dollars. 6th Mind delivers the same category of stimulation through hardware most people already own: a smartphone.
Until now, the app produced light through the camera flash. Version 2 adds headset mode, which runs sessions through the phone’s display instead. The user places the phone into a 3D-printable headset that holds the screen close to the eyes and blocks out surrounding light. The display splits into two halves, one per eye, with patterns pulsing at the session’s frequency. Each frequency band receives its own color, chosen for visibility through closed eyelids, and the display’s brightness and refresh rate keep the flicker sharp from one hertz up to the physical limit of the screen.
The headset consists of two 3D-printed parts: a universal body and a holder matched to the phone model. It can be printed at home for a few dollars of filament or ordered from a printing service for around 30 dollars.
“The most capable audio-visual entrainment device most people can own is already in their pocket,” said Maria Georgieva, founder of 6th Technology. “We set out to build the most affordable AVE system a person can own, and the most advanced one that runs on hardware they already have. Modern phone screens are bright, fast and precise. Version 2 finally puts them to work.”
Headset mode also enables sessions with open eyes. Unlike the high-intensity strobes used in dedicated AVE hardware, a phone screen is a soft, diffuse light source whose brightness the software lowers to a comfortable level. Decades of research on the brain’s response to rhythmic light, measured as the steady-state visual evoked potential, has been conducted with participants watching flickering screens with their eyes open (Notbohm, Kurths and Herrmann, Frontiers in Human Neuroscience, 2016), and recent at-home trials of 40 Hz gamma stimulation report the approach to be safe and well tolerated (He et al., Alzheimer’s and Dementia: TRCI, 2021).
Version 2 also introduces Mental 6-packs, sets of six sessions built around a single theme such as evening wind-down or daytime focus, along with the option to expand the app’s daily routine with additional sessions for mental clarity or sleep. The mental clarity sessions center on 40 hertz, the gamma-band frequency most consistently tied to attention and memory in recent research.
The final component of the release lives outside the app. The new Session Library on the company’s website catalogues every session and pack 6th Mind offers, each with its purpose and frequency profile. The app’s 36 default sessions play directly in the browser, and packs installed from the library appear in the app automatically.
The sessions in 6th Mind are built on data from the company’s practice office in Sofia, where more than 800 AVE sessions have been measured with EEG recordings taken before and after each one. The company positions the app as a complement to professional mental health care, not a replacement for it.
“Evidence-based brain stimulation should not be locked behind expensive equipment,” said Georgieva. “Version 2 is the biggest step toward that goal so far. The deepest experience the app offers now costs no more than a piece of printed plastic.”
6th Mind version 2 is available on the App Store and Google Play. Details on the release are published in the official announcement, and the 6th Mind app page provides download links for both platforms.
About 6th Technology
6th Technology is a mental health technology company based in Sofia, Bulgaria. The company develops audio-visual entrainment software grounded in its own clinical practice, where sessions are measured with EEG before and after use, and offers in-person AVE sessions at its practice office in Sofia. Its 6th Mind app for iOS and Android provides science-based brainwave entrainment sessions at no cost, with no advertising.
