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Previous investigations identified that insufflation of the esophagus may elicit reflex pharyngoesophageal closure, impeding airflow and subsequent voice production. A simplified method for esophageal insufflation consistently evaluates the capacity for alaryngeal speech acquisition. Although primarily a method for predicting tracheoesophageal speech, it may also be an important prognostic indicator for traditional esophageal speech development.
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Blom et al. (1985) studied this question.
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