Measuring The Sound Power Level Of Chinese Bowed Stringed Instruments In A Semi-anechoic Chamber

The origin of Chinese traditional musical instrument can be traced back to primitive times, through the development of dynasties; they have been completed to self-contained and have their own unique charm. Chinese folk music is increasing concerned by overseas individuals. However, the Chinese traditional music instrument has been lagging far behind Western countries and neighboring countries in Asia and available basic data is very limited. Deep study and measure of the national music instruments will further protect and promote the nation's music culture.Study and admeasurements of sound pressure level and sound power level and directivity of national instruments can provide important basic data for the hall's sound quality research. International systemic measurement of the Western instruments'sound power level has been gradually carried out. However, due to the differences characteristics in different musical instruments and culture, these data can not be directly used for Chinese traditional musical instruments. Since 2004, some basic data have been gained from the systematically measurement of a number of important national instrument'sound power level in reverberation room of South China University of Technology. Sound power level of musical instruments depends on both instrument itself and performance skills and their understanding of the intensity. So a different acoustic environment will get different measurement. We choose to measure the sound power level and the directivity of the main national instruments in anechoic chamber.The first systematic measurement for determining the sound power level of seven kinds of typical Chinese bowed stringed instruments in a semi– anechoic chamber is reported in this paper. Two professional musicians performed on their own instruments respectively. Ten-channel acoustical equipment were used to measure the sound pressure level spectrum synchronously when some single notes, music scale and melodies are performed under pp, mp, f and ff dynamics respectively. The radiated sound power levels and dynamic ranges of each instrument were then obtained through calculating. The results of Erhu,Zhonghu,Yehu and Zhongyinbanhu was reported particularly here. And typical sound power levels, dynamic range and spectrum were given. Besides, the radiated spectrum of Gaohu,Zhongyinbanhu and Yehu was given when music scale are performed under f dynamics.The measurement results show that the average result of the forte sound power level of performing music scale in a reverberation chamber and in a semi– anechoic chamber is the most representative value of the sound power of instrument. The average result of typical sound power level values and SWL dynamic range of the seven Chinese bowed stringed instruments was given, and these results can provide a basic data for the further research of our national instruments and for the performing of national band and for the acoustic assessment of the national hall.