Complex Inter-relationships Between Vital Capacity, Maximum Phonation Time, and Phonation Quotient

Abstract

Normal values of maximum phonation time, vital capacity, and phonation quotient were obtained for college students. Relationships between these various measures were examined. A moderate relationship between vital capacity and maximum phonation time was established. Vital capacity was chosen as the factor to represent respiratory abilities, because this measure can be easily obtained with a compact spirometer. It is possible that another respiratory measure, such as phonation volume, may be more indicative of respiratory abilities as related to phonation. It was determined that ranges of maximum phonation time and phonation quotient could not be established for vital capacity groups.