| Themes > Science > Physics > Acoustics > Physical Characteristics of sound > Quality |
If A above middle C is played on a violin, a piano, and a tuning fork, all at the same volume, the tones are identical in frequency and amplitude, but very different in quality. Of these three sources, the simplest tone is produced by the tuning fork, the sound in this case consisting almost entirely of vibrations having frequencies of 440 Hz. Because of the acoustical properties of the ear and the resonance properties of the ear's vibrating membrane, however, it is doubtful whether a pure tone reaches the inner hearing mechanism in an unmodified form. The principal component of the note produced by the piano or violin also has a frequency of 440 Hz, but these notes also contain components with frequencies that are exact multiples of 440, called overtones, such as 880, 1320, and 1760. The exact intensity of these other components, which are called harmonics, determines the quality of the note. |
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