40 Hz sits in the gamma band, the fast oscillation the brain shows when perception binds into a single, vivid whole. Laboratory research, most visibly the MIT GENUS studies, has probed 40 Hz sensory stimulation, though that work is early and not a consumer-audio claim. Here it is simply a musical tempo of alertness: a steady forty-times-a-second pulse to work, focus, or wake up beside. Gamma oscillations near 40 Hz appear in the brain during focused, bound-together perception, and a line of laboratory research (notably the MIT 'GENUS' studies) has explored 40 Hz sensory stimulation in animal and early human work. Auriviel presents 40 Hz as a musical pulse to sit with (a tempo of attention) and makes no clinical claim from that research. Independent of any tradition, controlled clinical evidence that a specific frequency produces a specific health effect is limited and mixed. Auriviel presents these tunings as music and contemplative practice. This page is for general information and relaxation. Auriviel's frequency music is not medical advice, diagnosis, or treatment, and no health outcome is claimed. If you have a medical concern, please consult a qualified professional.