一种吉他调音器的设计与实现

摘要

A guitar tuner based on spectrum analysis is designed in this paper.ln the system,the original chords sound signal is filtered to remove the noise interference firstly.Then,the endpoint detection based on Short-time Energy and Zero-crossing Rate is carried out to detect the effective chords sound signal.Furthermore,a method of measuring the basic frequency is proposed that improved autocorrelation is used in the part of low frequency and harmonics peak value method is utilized in the high frequency to acquire pitch frequency.%对于传统的吉他调音只能依靠听觉去识别音高，存在着局限性强且准确性不高的缺点，设计并实现了一种基于频谱分析的吉他调音器。系统首先对原始弦音信号进行滤波以去除噪声干扰，然后使用短时能量和短时过零率进行端点检测，在此基础上提出了分段式基音频率的检测方法：低频段采用改进的自相关法，而高频段采用谐波峰值法来获取弦音信号的基音频率。测试结果表明，校准后的吉他弦音频率与标准频率误差为1．92‰，达到了预期的设计要求。