A few years later, Robert Monroe, with the assistance of Thomas Campbell and Dennis Mennerich
, researched the effects of binaural beats on consciousness. Like the ancient cultures of Tibet and India they found that these rhythmic pulses are a great tool for reaching altered states of consciousness. Their research was focused on the reproduction of a subjective impression of a 4Hz oscillation that they associated with out-of-body-experiences. They subsequently created the binaural beat self development industry, and formed The Monroe Institute, a binaural beat research and education organisation.