When two notes are not quite in unison the resulting sound is found to alternate between a maximum and minimum of loudness recurring periodically.
As a result, many audiophiles have never heard music with proper loudness compensation.
If the tones had no existence outside the ear then resonators would not increase their loudness.
In some domes, for instance in a dome at the university of Birmingham, a sound from one end of a diameter is heard very much more loudly quite close to the other end of the diameter than elsewhere, but in St Paul's Lord Rayleigh found that " the abnormal loudness with which a whisper is heard is not confined to the position diametrically opposite to that occupied by the whisperer, and therefore, it would appear, does not depend materially upon the symmetry of the dome.
Many alarm clocks have a sound adjustment feature that allows the loudness of the alarm to be turned up or down.