Closed-Loop Auditory Stimulation

Pioneered by Ngo et al. (2013) and Tononi’s group at University of Wisconsin, closed-loop auditory stimulation delivers precisely timed sound pulses during deep sleep (N3). The sound syncs with the up-phase of your brain’s slow oscillations, amplifying them naturally. NextSense is the first to put this technology in a consumer earbud.

Real EEG, Not Accelerometer Guessing

Most sleep trackers use motion sensors to estimate sleep stages. SmartBuds use 6 medical-grade EEG sensors that measure actual brainwaves at 250Hz — the same technology used in clinical sleep labs. We detect N1, N2, N3, and REM with peer-reviewed accuracy validated against clinical polysomnography.

Our Data: 46 Users, 4 Weeks

Across 46 active users over 4 weeks, SmartBuds delivered an average of 920 slow waves per session with a slow wave rate of ~144/hour — consistent regardless of how often users wore the buds. Even casual users who wore SmartBuds once per week received comparable slow wave benefit to daily users.

Experience the Science Yourself

See your own brainwaves. Feel the difference in the morning.

30-night risk-free trial • Free shipping • Named to Oprah’s 2026 Sleep Awards