Study of the small sound box of Erhu and its function

• Main Author: 霍柄成
• Other Authors: 鄭德淵
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/98265605399822764735

碩士 === 國立臺南藝術大學 === 民族音樂學研究所 === 96 === Since the end of 50s, many Chinese erhu experts had dedicated to the renovation of this instrument. The shape as well as the design of erhus has a noticeable impact on the coupling of acoustic waves; however, it was not scientifically proven and documented. In 1975, erhu master Man Reising’s innovation of a dual-sound box erhu has achieved better consistency of acoustic volume with its middle range and treble range. Man has added an extra phyllostachys makinoi hayata sound box in hope of improving its sounds, but the sound effect did not work as well as expected. Yang Yi had published his test results of phyllosatchys makinoi hayata erhu in the journal “Yuechi” (musical instrument). Furthermore, this improvement does not benefit the volume of the treble range notes. Yang Yi concluded from his experiment that the sound box actually serves as a filter. Hence the author decided to challenge this hypothesis and further Yang’s experiment. In chapter one, various types of sound boxes of Chinese bowed stringed instruments, history of erhu and acoustic characteristics of types of erhus are investigated and studied. Even though the thesis has focused on the modern erhus which are designed for the purpose of stage effect and differ from the conventional/traditional erhus. Numerous types of sound boxes may be found in Chinese bowed stringed instruments. It is imperative to clarify them individually. Chapter two studies the manufacturing process of erhu and the material used to make it. The analyses identified the origin and specific types of phyllostachys makinoi hayata (bamboo) and redwoods used to make this instrument. In Chapter three, sound boxes in different lengths and that of diverse materials are tested. In the experiment, the sounds were being recorded and converted to wave file format (.wav) and then the results were compared with a B& K spectrum analyzer. The readings of frequency of harmonics series and dB values were recorded in a table. In chapter four, the mean of collected data was compared and interpreted to explain the filtering effects of the sound boxes in half of its original length in order to counter- prove the hypotheses proposed by the author and Yang that , in fact, the sound box of erhu only serves as a filtering device. The author also made suggestions and conclusions as the reference for future extended investigation.