這個討論串討論了不少 Accurate frequency detection理論與實作上的建議

http://www.dsprelated.com/groups/audiodsp/show/792.php

內容很有趣, 可惜實在是沒什麼時間仔細咀嚼,
Anton建議了三篇論文, 先紀錄下來吧
stefan uppgard - Implementation and analysis of pitch tracking algorithms
david gerhard - Pitch Extraction and Fundamental Frequency: History and Current Techniques
P J Kootsookos - A review of frequency estimation and tracking problems