Why when I have music on in earphones and I have them resting on a desk, the music sounds different, like in a different tonality/pitch to when I am actually using them?
Ron is not far off the mark but I have always thouught it was the difference between inductive and radiative coupling. A free-standing speaker must couple all energy into the air, where the field attenutates as 1/r. In the near field zone, however, inside this wavelength, there is also the inductive field, which attenutates as 1/r-squared. If you are far from the speaker this component becomes negligible, but in the near zone, it is still effective. That's why you can transmit from the earphone to the eardrum. It still goes through the air, it's just takes advantage of the near-field effect.