古鈸打擊聲音特性之探討

Discussions on Percussion Sound Characteristics of Crotales

王栢村(Bor-Tsuen Wang) ； 吳祥瑞(Shiang-Ruei Wu) ； 徐秀娟(Shiou-Jiuan Shiu) ； 高正賢(Jeng-Shian Gau)

《中華民國振動與噪音工程學會論文集》 2011 (2011/06) Pp. 94-99

https://doi.org/10.30028/CSSVANNUAL.201106.0094

摘要

古鈸屬於有調打擊樂器之一，由不同大小的金屬製小圓鈸組成，並按照音高鍵盤次序排列，有兩組八度音12個音階，其每個古鈸尺寸約為4英吋，構造為圓形頂面與底面中心則為中心孔，材料為青銅或黃銅。本文旨在描述一套古鈸打擊樂器，首先，利用精密麥克風做為感測器，對古鈸進行敲擊之聲音量測分析，透過頻譜分析儀，求得古鈸之聲音頻譜及峰值頻率，並針對古鈸聲音的音高、音色、持續度三大部分分別進行探討，同時運用有限元素分析，將古鈸以立體元素建構其有限元素模型，並設定固定邊界，以進行理論模態分析，求得該古鈸之模態參數，包括自然頻率及所對應之模態振型，並將實驗所求得之峰值頻率為基準修正於有限元素模型，經由有限元素分析運算所得知結果顯示，其理論有限元素與實驗所得知模態參數相當吻合。因此，可以進一步了解到古鈸的聲音與振動模態特性的相關聯性與聲音品質，未來可提供其他樂器設計之聲音與振動特性間之關連性的研究。

關鍵字

打擊樂器 ； 古鈸 ； 自然頻率 ； 阻尼比

並列摘要

Crotales or antique cymbals are tuned percussion instruments. Each crotale is about 4 inches in diameter with a flat top surface and a nipple on the center base and made of bronze or brass. This paper aims to characterize the percussion sound of a set of crotales. The sound measurement is carried out by using the precision microphone mounted to the commercially available FFT analyzer to obtain the percussion sound spectrum and peak resonances. The pitch, timber and decay effects for each crotale are discussed. Finite element analysis (FEA) is also applied to perform theoretical modal analysis on the crotale in real boundary. The numerically obtained modal parameters, including natural frequencies and mode shapes, can be compared with those from experimental data for validating the FE model. Results show the modal properties and percussion sound spectrum can be well interpreted for the relation between the sound and vibration characteristics. Therefore, the percussion sound quality of crotales is calibrated. The presented analytical approach can be applied to other percussion instruments in the future.

並列關鍵字

percussion instruments ； Crotales ； natural frequencies ； damping