乐器辅助学习器音调保持算法的设计与实现  

Design and Implementation of Tone-preserving Algorithm for Musical Instruments Aiding Learning Equipment

作　　者：靳思雨 韩宇龙[1] 吴秉坤 苗洪睿 党柳 邵淑颖 宗天禹 JIN Si-yu;HAN Yu-long;WU Bing-kun;MIAO Hong-rui;DANG Liu;SHAO Shu-ying;ZONG Tian-yu(School of Information Science and Technology,North China University of Technology,Beijing 100144,China;School of Microelectronics,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]北方工业大学信息学院,北京100144 [2]中国科学院大学微电子学院,北京100049

出　　处：《工业技术创新》2020年第6期121-126,共6页Industrial Technology Innovation

基　　金：2020年北京市级大学生创新创业训练计划项目

摘　　要：多普勒效应的存在,使得音频在加速或减速播放时,音调变得尖锐或低沉,无法满足很多场景的应用需求。以乐器辅助学习器为研究对象,兼顾考虑软件复杂程度和硬件实现成本,优选时间域的剪贴法,设计2倍速和1/2倍速下的音调保持算法;以有限时长二胡乐曲为例,采用改变音频速度时变调的普通算法和音调保持算法进行音频处理,并对处理结果进行对比分析。研究发现,普通算法2倍速(或1/2倍速)处理得到的音频频率范围明显拓宽(或收窄),同时在原始频率范围内的高频(或低频)段出现了1~2个显著的频率分量,为音调变尖锐(或低沉)提供了理论证据。音调保持算法基本达到了预期效果,实现了“变速不变调”,并且处理步骤简单、易于硬件集成,为乐器辅助学习器等产品的音效处理模块提供了开发思路。The existence of Doppler effect makes the tone become sharp or deep when the audio is playing in acceleration or deceleration,which cannot meet the application requirements of many scenarios.Taking musical instrument aiding learning equipment as the research object,considering the complexity of software and the cost of hardware implementation,the clipping method in the time domain is selected out,and the tone-preserving algorithm under the speed of 2 times and 1/2 times are designed;taking the limited length Erhu music as an example,the general algorithm which will change the tone when changing the audio speed and the tone keeping algorithm are used to process the audio,and the processing results are compared and analyzed.It is found that the frequency range of the audio processed by the general algorithm is obviously widened(or narrowed),and there are 1~2 significant frequency components in the high band(or low band)of the original frequency range,which provides theoretical evidence for the tone to become sharp(or deep);the tone-preserving algorithm basically achieves the expected effect,realizes“variable speed without changing tone”.Its processing steps are simple,and it is easy to integrate hardware,which provides a development idea for the sound processing module of musical instrument aiding learning equipment.

关 键 词：音调保持算法 多普勒效应 乐器辅助学习器 时间域 剪贴法 变速不变调 

分 类 号：TN912[电子电信—通信与信息系统]