> Zemlin states that one of the main purposes of the TA muscle is that of a > (longitudinal) tensor. > > Randy Buescher
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Dear Randy and listers,
I think our disagreement here is more a matter of semantics:) I comletely agree with your Zemlin quote above. His book, "Speech and Hearing Science" is a very important addition to the literature. Some recent scientific research has found that Fo control for singing is different from control for speech. And speech research is Zemlin's area of focus.
In describing the CT Zemlin writes, "the distance between the thyroid cartilage and the vocal processes is increased to elongate the vocal folds....action that is necessary for pitch changes."
In the Hirano EMG study (1969) they found that Fo was primarily controlled by CT...while the LCA and TA were of secondary importance. Shipp and McGlone (1971) found that CT and TA muscles act synergistically to regulate Fo, but that CT is primary and TA is secondary. So it appears that while CT is most positively related to Fo, TA comes in a close 2nd, as the Zemlin quote implies.
In his 1988 paper from Journal of Voice, Hirano includes this helpful table of laryngeal muscle action-
CT VOC (TA)
Length Elongate Shorten Thickness Thin Thicken Edge Sharpen Round Muscle (Body) Stiffen Stiffen Muscosa (cover + transition) Stiffen Slacken
Great discussion!
Taylor L. Ferranti Certificate of Vocology DMA Candidate in Voice Science/Voice Performance Louisiana State University
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