消声室测量法研究弦槌对钢琴声音的影响

为研究弦槌性能,有很多研究者采用了各种机械测量方法,而本论文则希望通过声学测量方法来研究。我们实测了两套不同弦槌对钢琴声音频谱的影响,具体做法是在消声室中使用3种力度弹奏88个琴键并进行录音。频谱分析的结果表明两套弦槌在中力度弹奏时得到的频谱基本一致,但在大力度和小力度弹奏时差别较大,其差别表现为：在低频端,珠江钢琴弦槌激发的高次谐波分量要大于并多于德国Abel公司生产的弦槌;随着频率的升高,该现象逐渐减弱,并出现相反的现象。根据Donal E. Hall的弦槌理论可知,造成这些差异的原因是弦槌硬度和初始能量的影响效果在不同力度下有所不同,如欲考察弦槌宽度和质量的影响适合在大力度下弹奏,而考察弦槌硬度的影响适合在小力度下弹奏。实验结果表明,这种声学测量实验方法主要使用常规的声学仪器,具有简单、易行的优点,可以作为辅助弦槌的设计和改进工作的一种有效方法。

Measurement in anechoic chamber to research the effects of chord hammers on piano sound

Many researchers used to research chord hammers by mechanical measurement devices. The authors want to do it by usual acoustical method. We measured the difference between 2 kinds of chord hammers. We recorded the sound pressure while all 88 keys were being performed under 3 kinds of dynamics. It is suggested by the result of spectrum analysis that these 2 chord hammers were identical under medium dynamic and the difference showed up just under weak dynamic and strong dynamic. In detail, Pearl River Piano chord hammer stimulated more and stronger higher harmonic waves than the Abel(German chord hammer brand) chord hammer at the bass end. It decreased and the opposite situation appeared with frequency rising. According to Donald E. Hall"s chord hammer theory, it is because of the different effects of hammer compliance and initial energy under different dynamics. Besides, strong dynamic is better for observing the effects of wideness and mass of chord hammers while weak dynamic is better for effects of hammer compliance. It can be concluded from the result that this experimental method is a doable and easy way to help design and improve chord hammers.