母音共振峰變化與胸聲、頭聲、假聲共振峰關係

http://themodernvocalistworld.com/2010/05/31/male-voice-passagio-101-where-is-it-and-why/

http://themodernvocalist.punbb-hosting.com/viewtopic.php?id=7395

chest like qulity H2<f1
head  like qulity f1<H2<f2
falsetto like qulity f2<H2
flageot like qulity f1<H1

共振峰頻率變化與vocal track
http://www.ncvs.org/ncvs/tutorials/voiceprod/tutorial/rules.html