Spatial Angle Modulation SAM is the Institute's newer audio method: one tone moved through stereo space instead of two tones beating. Controlled evidence so far is limited. Spatial Angle Modulation, or SAM, is an audio method developed at the Monroe Institute as a complement to Hemi-Sync. Classic Hemi-Sync builds its signals from binaural beats: two slightly different tones, one in each ear, that the brain combines into a slow beat. SAM instead uses a single tone that is digitally moved around the stereo field. In Skip Atwater's 2012 description in the TMI Journal, the apparent source of the sound swings faster than the brain can follow, and the brain responds with a rapid flutter in the tone, a tremolo similar to binaural beating. Nancy McMoneagle, a longtime Institute leader, put it more simply: a single tone that sounds as if it is moving through space. The Institute began investigating the method in 2008, looking for an audio support that would extend the range and flexibility of its seminar programs. Atwater and co-inventor Mike Turner developed it, and by 2013 trainer Bob Holbrook was presenting version 2.0 at the Professional Seminar. SAM is the audio behind the Institute program Event Horizon. It can be combined with music, nature sounds, pink noise and spoken guidance, and in 2012 the Institute said it would not replace Hemi-Sync products.
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Spatial Angle Modulation
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The evidence for SAM is thin, and the Institute's own people say so. Atwater's 2012 article is a design rationale that expected objective evidence from later studies of gamma synchrony. In a talk posted in 2018, researcher James Lane said three studies of his looking for relaxation effects had not shown powerful effects. A small pilot using a mystical-experience questionnaire, with 14 participants and no control group, found that seven met the criteria for a complete mystical experience. For now SAM is best understood as a different way of building the sound, backed by design theory and participant reports rather than controlled results. One moving tone instead of two beating tones Classic Hemi-Sync, as A.J. Honeycutt described it in 2014, combines Bob Monroe's voice, a bed of phased pink noise and the Hemi-Sync signals themselves; Focus 10, for example, uses a mix of delta and theta signals. Those signals are binaural beats. Atwater's 2012 article says SAM instead uses a single carrier tone whose apparent position is moved digitally through a stereo field. Because the position changes faster than the brain can track, the listener hears a tremolo, which Atwater calls similar to binaural beating. Five adjustable settings, against two