Acoustical behavior of brass player's lips.
Acoustical behavior of brass player's lips.
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铜管乐器演奏者嘴唇的声学行为。
DOI：
10.1121/1.412066
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
S. Yoshikawa
中科院分区：
文献类型：
--
作者：
S. Yoshikawa
铜管乐器演奏者的嘴唇运动最好是外击还是上击，这一有争议的问题是通过测量吹口压力和嘴唇位移之间的相位差来解决的。与谐振系统的输入阻抗的相位类似，该相位差的负/正值表明向外冲击/向上冲击振荡。实验结果表明：（1）由于唇口的高柔性，在无吹嘴的情况下，大唇口驱动管道同时支持外击和上击振动：（2）吹嘴-非共振管道系统在很宽的频率范围内几乎支持外击振动;（4）圆号和小号在最低阶振型下表现出向外振型，在较高阶振型下表现出向上振型。铜管乐器中的振荡过渡主要取决于唇口的非线性声阻抗，它与吹口压力波形从低音调、非正弦波形到高音调、更正弦波形的变化有很好的对应关系。如果它的幅度可以忽略，则吹嘴杯和演奏者的嘴之间的腔耦合产生有利于向外打击振荡的电容性输入阻抗;如果它的幅度显著，则腔解耦可能产生有利于向上打击振荡的惯性输入阻抗。由于唇口处随时间变化的伯努利压力和接收该压力的区域两者通常倾向于随着吹制压力的增加而增加，因此向上打击的振荡倾向于主导铜管乐器中的较高模式音调。
The controversial problem of whether a brass player's lip movements are best modeled as outward striking or as upward striking is approached by measuring the phase difference between mouthpiece pressure and lip displacement. In analogy with the phase of the input impedance to a resonant system, the negative/positive value of this phase difference suggests an outward-striking/upward-striking oscillation. On the basis of this speculation, the experimental results revealed the following: (1) Large lip-driven pipes support both outward-striking and upward-striking oscillations because of the lip's high flexibility in the absence of a mouthpiece; (2) mouthpiece-nonresonant tube systems almost support the outward-striking oscillation over a wide frequency range; (3) mouthpiece-resonant tube systems totally support the outward-striking oscillation; (4) the French horn and trumpet exhibit the outward-striking oscillation for the lowest mode and the upward-striking oscillation for higher modes. The oscillation transition in brass instruments, which corresponds well to the change of mouthpiece pressure waveform from a low-pitch, nonsinusoidal one to a higher-pitch, more sinusoidal one, depends mainly on the nonlinear acoustic impedance of the lip opening. If its magnitude is negligible, the cavity coupling between the mouthpiece cup and player's mouth yields a capacitive input impedance that favors the outward-striking oscillation; if its magnitude is significant, the cavity decoupling is likely to yield an inertive input impedance that favors the upward-striking oscillation. Since both the time-varying Bernoulli pressure at the lip opening and the area receiving this pressure are generally apt to increase as the blowing pressure increases, the upward-striking oscillation tends to dominate higher mode tones in brass instruments.