On The Relevance Between The Sound And The Shape, Material Of The Acoustic Resonator Of Erhu

Erhu, first appeared in the Tang Dynasty (618 - 907AD), is a popular string musical instrument in China and is widely used in solo, ensemble and accompaniment of opera, folk music, etc. The instrument is famous for the resemblance between its tone and human voice,which makes the performance immensely touching. The instrument is extremely expressive and is applicable to both deep,melancholy content and grand, joyful scenes. Since 1949, Erhu has received great development and has now become the most widely used and most influential folk musical instrument.This thesis focuses on the studies of the acoustic resonator of Erhu. The research has been carried out through site visiting and experiments. It makes use of various measuring techniques of Music Acoustics to explain the features of the acoustics of Erhu, including the relationships between the shapes, material and manufacturing details of the acoustic resonator and acoustics of the instrument. Based on these facts,the thesis further investigates the associations between the shapes,material of acoustic resonator of Erhu and its acoustics, in order to provide basis and new directions in terms of the improvement of the instrument.The thesis consists of 5 chapters:Chapter 1 is an introduction. It explains the purpose of this research in detail,including the research scopes and methodologies. It also provides a review of the existing literatures on this topic.Chapter 2 describes the development of Erhu over the years and its current state.It explains the features of the instrument and how the sound is employed,through a detailed explanation of its acoustics, from vibration, transmission, resonance,incitation to adjustment.Chapter 3 explains the influence of the acoustic resonator of Erhu on its sound.The first section of this chapter describes the acoustics properties of the hexagon acoustic resonator (southern style), the octagon front round back acoustic resonator and the oval shaped acoustic resonator. The second section introduces the features of the hexagon acoustic resonator (northern style) and compares it to the hexagon acoustic resonator (southern style). This comparison reveals the reasons behind the inevitable popularity of the southern style acoustic resonator over the northern style acoustic resonator. In the third section, acoustic measures of the experimenting instrument are reported. The impact of the shape and depth of the acoustic resonator on the sound of Erhu is illustrated based on these measures.Chapter 4 explains the influence of the material of the acoustic resonator, wood and snake skin, on the sound of Erhu. The first section introduces the physical properties of some commonly used wood material, such as aged Dalbergia cochinchinensis Pierre ex Laness, Red Sandalwood, Ebony and Acer Mono. It the analyses the difference between the acoustic resonator manufactured using various types of wood through audio frequency samples. The second section introduces the physical properties of the snake skin, explaining the influence of its thickness and tension on the sound or Erhu. It then lists the merits and drawbacks of using natural snake skin as the resonance film of the instrument.Chapter 5 concludes the thesis.