Apparently the sound of the Earth resonates within the 100km sonic concentric tunnel that encircles and is a part of the Earth - commonly known as the atmosphere, it being the space before "space" technically begins. The caverns beneath the Earth's surface also amplify this beat and it is broadcast around the Earth from those resonating cavities.
The interesting part is that without this beat we become ill, disorientated, and we eventually die! This has been fully researched and even NASA fits each spacecraft with a Schumann simulator which exposes astronauts to the 7.8 hertz heartbeat that we feel at all times, therefore keeping them well!
The Schumann resonance is like a tuning fork for the Earth, meaning it has natural frequencies for electromagnetic radiation, and as it turns out the human brain has exactly the SAME natural frequencies! Wow...
There is alot of scientific research about the Schumann resonance as it has a direct correlation to lightening storms and also the transmission of radio waves and the like, which you are welcome to investigate further if it interests you, however for me the curiosity lies more in the underlying fact that the Earth has a heartbeat that is constantly pulsing and keeping us connected and alive! AMAZING!
What is disturbing though is the thought that we could possibly be altering this natural rhythm by using electronic devices that disturb the frequencies we live in... Many people get headaches from using computers and mobile phones and with the number of electronic devices in one room in the average household I'm not surprised that we are affected eventually! My Mum always brought us up to switch off appliances at the powerpoint if we were not using them and although this was for an energy saving purpose I also think it is a good idea to reduce the amount of electronic 'clutter'. I now also switch off all powerpoints before I go to sleep at well as it disrupts your sleep having electric currents and radiation constantly flowing around you.
So I guess the things to take home are that ultimately from the moment we arrived on this Earth our own bodies synced in with the Earth's natural rhythms and continue to do so of their own accord! So be kinder to Mother Earth - she is keeping you alive and well =)