Piano Acoustics

Piano Acoustics

Piano stands for a musical instrument better known as a keyboard or a synthesizer. It produces sounds by the application or striking the steel strings with felt hammers that immediately rebound facilitating the continuation of vibrating sound at its resonant frequency. These vibrations then travel through the bridges to the sound board which serves as an amplifier. Piano is short form of Pianoforte - an Italian word.

Working

Acoustics of piano refer to the various physical properties of piano which affect the sound generation and propagation factors. This usually consists of the dimensions, thickness, tenderness of strings, inter-synchronization and other factors. The key when depressed pushes other components which further tend to set the other mechanics in vibration. The vibrations are then carried to the bridge which then amplifies the sound. In general, initially the key of piano if pressed down, this raises the damper. The hammer connected to it is thrown against the string. The rebounding hammer thus is made to produce the sound of a sine wave.

Elements of piano acoustics

The first element is the string motion which can be visualized like the figure of a sine-wave. The striking of the key deforms the string at that point resulting in two waves traveling out in opposite directions. This redefined sound arising out of the key being struck, decides the frequency of the generated sound. The next factor is that of pitch and harmonicity. The piano string has a preferred set of vibrations or resonance ranges. When any key is depressed the result is generation of simultaneously sounding sine waves. Another important factor is of sound radiation and impedance mismatch. The impedance gives the know-how of the degree to which string resists motion. This factor is used of to strike the surface with optimum pressure. Loudness of the generated sound also governs the pleasant and melodious attributes of the sound. The high tension in the strings of the piano increases the stored energy of vibration and thus required harmonics are achieved. Perfect harmony of strings is not desirable, thus a little in-harmonicity provides rich tunes and melodies. However, periodic oscillations of the string produce the desired pleasant sounds.

Piano Playing