The piano consists of the following mechanisms : ( a )transmissien of energy from the hammer to the strings , ( b ) propagation of energy on the strings , ( c) tran8mission of energy from the strings to the 80undboard at the bridge , and ( d) acoustic radiation by the vibration of the soundboard . These meehanisms are expressed in terms of an equivalent electric circuit model , which is simulated by computer programs . A nearl . y half . sinusoidal pulse which is produced by the hammer ' s

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... e , propagates on the speciat transmission line , and is refiected by the impedance of the bridge and the 血 【ed end . The transmission and reflection Iead to the transformation and decay of the waveform . The driving velocity of the soundboard is made by supplying the summing forces of the strings at the bridge to the driving point i皿 pedance . This veioc ... ty produces the sound pressure whose waveform is determ 玉 ned by trans :nission characteristics of the soundboard . Arti丘cial piano sound is produced from calculated waveforms by a D − A conver − ter . When each funda皿 ental frequency of the group of strings i8 slightly detuned , beats are predueed in each partial which is inhar皿 onic . The changes are slow in the lower partials , but the highe ; they become , the rapider their changes are The decay rate of the sound is fast at the prompt sound , but it become8 slewly at the after sound . These a τ e some causes that gives a delicate timbre to the Plano ・