Humming · breath · autonomic rhythm
Humming, breath, and the vagus nerve
Humming turns the out-breath into a gentle, audible guide. With the jaw and throat relaxed, a comfortable hum naturally favors a slow, steady exhale. The vagus nerve is a major parasympathetic pathway connecting the brainstem with the heart, lungs, and digestive tract.
Breathing and heart rhythm are linked: heart rate normally shifts across each breath. Studies of voluntary slow breathing report short-term changes in heart-rate variability consistent with cardiovagal modulation. Humming also increases airflow between the nasal cavity and sinuses and can temporarily raise nasal nitric oxide.
Use the Hum voice as sensory feedback rather than a pitch to force. Keep the breath easy, let each exhale end on its own, and return to normal breathing if you feel light-headed, strained, or short of breath.
EEG orientation
A brief guide to brain rhythms
EEG recordings are often discussed in broad frequency bands. The boundaries vary between studies, and each band can appear in different brain regions and activities.
Deltaabout 0.5–4 HzSlow activity most prominent during deep non-REM sleep.
Thetaabout 4–8 HzCommon during drowsiness and light sleep; waking theta also participates in memory and cognitive control.
Alphaabout 8–13 HzOften strongest during quiet, eyes-closed wakefulness and reduced by visual or active attention.
Betaabout 13–30 HzFaster activity common during alert wakefulness, active thought, and sensorimotor processing.
Gammaabout 30 Hz and aboveFast activity studied in perception, attention, memory, and local network coordination.
Context matters. These are approximate EEG categories, not five separate states of mind. Several rhythms coexist. An audio beat frequency is not an EEG measurement and does not guarantee a matching brain state.