Wind Chimes

Wind chimes are chimes constructed from suspended tubes, rods or other objects and are often made of metal or wood. Wind chimes are usually hung outside of a building or house and are intended to be played by the wind. Sound can be produced when the tubes or rods come in contact with a suspended central clapper, in the form of a ball or horizontal disk, or each other. Wind chimes may be used to observe changes in wind direction, depending on where they are hung.

Modern wind chimes have their origins in Indian wind bells. By the second century CE, these wind bells were being hung on the corners of large pagodas with the purpose of scaring away birds and evil spirits. [1]. Later, wind bells were introduced to China and were also hung in temples, palaces and homes. Japanese glass wind bells known as F?rin (??) have been produced since the Edo period [2]. Wind chimes are thought to be good luck in parts of Asia and are used in Feng Shui.

Chimes produce inharmonic (as opposed to harmonic) spectra, although if they are hung at about 1/5th of their length (22.4%)[3], the higher partials are dampened and the fundamental is brought out. This is common practice in high-quality wind chimes, which are also usually hung so the center ball strikes the center of the wind chime's length. Frequency is determined by the length, width, thickness, and material. There are formulas that help predict the proper length to achieve a particular note, though a bit of fine tuning is often needed.

In instruments such as an organ pipe, the pitch is determined primarily by the length of the air column. It is the air that vibrates. The pipe material helps determine the "timbre" or "voice" of the pipe, but the air column determines the pitch. In a wind chime, the pipe itself is being struck and the air column has little to do with the sound produced.