from vince mrykalo: >>Bob Davis wrote: > I'm sure there are some subjective elements to the perception of "loudness" > at the attack, > but there are also some objective things. Because the hammer is compressed > more by the harder blow, it acts stiffer than at the soft blow, rebounds more > quickly from the string, and therefore produces more high partials. >You may be right, but how do you know the hammer rebounds more >quickly on a hard blow? Doesn't the hammer displace the string more >on a hard blow, and therefore is actually on the string longer? --- >vince mrykalo rpt ----------------------------------------------BOB REPLIES: The clearest explanations of the non-linear elasticity of hammer felt are in the lecture by Anders Askenfelt and Erik Jansson, and the one by Donald Hall, in the Five Lectures on the Acoustics of Music. Although you are right that the _amplitude_ of the displacement is greater for a loud blow, the contact time is actually shorter, by a factor of three or more. On middle C, the contact time for a pianissimo blow may be typically, say, 4 milliseconds, while at ff, the hammer is off the string in 1.5 milliseconds, creating a sound richer in high partials. Bob
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