Schumann Fundamental

What you are actually hearing

The two tones are roughly eight hertz apart, so the difference between them lands close to the 7.83 Hz figure the file is named for. Because each tone goes to a different ear, the slow pulse you notice is a binaural beat formed in your hearing rather than a sound present in the room — over speakers both ears receive both tones and the effect largely collapses. This is not a recording of the Earth. The real resonances are electromagnetic rather than acoustic, and at 7.83 Hz they sit far under the roughly 20 Hz lower limit of human hearing, so no microphone would capture them and no speaker could reproduce them.

What the research supports

Not much, and it is worth saying plainly. A systematic review of fourteen EEG studies of binaural beats found five results consistent with the entrainment hypothesis, eight contradictory, and one mixed; the authors described the literature as inconclusive at best and said effect sizes could not be inferred. Take this as a low, pulsing tone you may or may not enjoy listening to, and nothing beyond that.

For a plain pitch with no beat in it, try the 174 Hz tone or the 396 Hz tone, and see the rest of the catalogue on the sound library index. If the bare beat feels thin, the Schumann tone under brown noise in the free sound mixer gives it something to rest against — though the beat still needs headphones to be heard as intended.