What are some topics Troy Clifford Dargin has discussed in his presentations?
Some topics Troy Clifford Dargin has discussed include Lessac in performance and therapy, and the effects of semi-occluded vocal tract exercises on vocal function in singers.
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What are some topics Troy Clifford Dargin has discussed in his presentations?

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Some topics Troy Clifford Dargin has discussed include Lessac in performance and therapy, and the effects of semi-occluded vocal tract exercises on vocal function in singers.<|im_end|>