Glass harmonica by rubbing glass or crystal goblets or bowls. The alternate instrument consisting of a set of wine glasses (usually tuned with water) is generally known in English as "musical glasses" or the "glass harp". When Benjamin Franklin invented his mechanical version of the instrument in 1761, he called it the armonica, based on the Italian word "armonia", which means "harmony". The unrelated free-reed wind instrument aeolina, today called the "harmonica", was not invented until 1821, sixty years later. The word "hydrodaktulopsychicharmonica" is also recorded, composed of Greek roots to mean something like "harmonica to produce music for the soul by
Glass harmonica and locate ranges of sounds. Above 4 kHz people primarily use the "loudness" of the sound to differentiate between left and right ears and thus triangulate, or locate the source. Below 1 kHz, they use the "phase differences" of sound waves arriving at their left and right ears to identify location. The predominant pitch of the armonica is in the range of 1–4 kHz, which coincides with the sound range where the brain is "not quite sure", and thus listeners have difficulty locating it in space (where it comes from), and discerning the source of the sound (the materials and