Glass harmonica the result would be musical cacophony. This modification also made it much harder to make the glass "speak", and muffled the sound. In 1975, an original armonica was acquired by the Bakken Museum in Minneapolis and put on display, albeit without its original glass bowls (they were destroyed during shipment). It was purchased through a musical instrument dealer in France, from the descendants of Mme. Brillon de Jouy, a neighbor of Benjamin Franklin's from 1777 to 1785, when he lived in the Paris suburb of Passy. Some 18th- and 19th-century specimens of the armonica have survived into the 21st century.
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