- 會議論文
特殊設計簡諧倍頻鐵琴組之聲音品質評估
Sound Quality Evaluation for Special Design of Metallophone with Harmonics Sound
摘要
本文主要對具有特殊設計之簡諧倍頻音鐵琴組，其有三組八度音，進行聲音品質之客觀與主觀評估。首先藉由量測一個鐵琴片之打擊聲音頻譜，探討其聲音特性，鐵琴片的音準由第一個模態頻率界定，而高模態頻率與基礎頻率成整數倍數則為其泛音之組成，藉由探討鐵琴片打擊聲音之音準、音色及持續度探討其發聲之物理機制，同時也探討不同琴槌頭硬度對聲音頻譜之影響。此鐵琴組之各音階鐵琴片均呈現良好的音準，同時具有三個簡諧倍頻之泛音特性，此泛音頻率與音階之基礎頻率呈現整數比。各鐵琴片之音準也由專業音樂教師主觀評價認為相當準確，除有部分鐵琴片有聲音發散情形，此鐵琴組之打擊聲音確實有不錯的泛音特性。本文探討對鐵琴組之聲音品質客觀評估，未來也可應用到其他打擊樂器。
並列摘要
This work aims to evaluate the sound quality of the special designed metallophone that consists of three sets of octave musical scales by objective and subjective methods. The sound characteristic for one of the metallophone plates is first studied by measuring the percussion sound spectrum. The pitch of the metallophone plate can be characterized by the first modal frequency, and the overtone frequencies that are those natural frequencies of higher modes maintain integer ratios with respect to the fundamental frequency. The pitch, overtone and continuity of percussion sound for the metallophone plate are characterized to show its physical mechanism. The effect of different mallet hardness on percussion sounds is also presented. The metallophone is shown with very good pitch frequency for each musical scale and revealed harmonics for the first three dominant frequencies. The overtone is in harmonics, i.e. the set of partials is whole number multiples of the fundamental frequency. According to the subjective evaluation, the pitch for each metallophone plate is quite correct. The percussion sounds generally reveal good content of overtone, except some metallophone plates may produce diverse sound. This work presents the evaluation of sound quality for the metallophone and can be applied to other percussion instruments as well.