Roentgenological observations on vocal fold length-changes with special reference to register transition and opedcovered voice

This paper examines the length-changes of the vocal folds as a function of voice pitch. Changcs in normalized vocal fold elongation (strain) were measured indirectly from calcification points in several laryngeal structures from roentgenological exposures during singing. Changes in vocal fold strain are shown to occur mainly in the register transition area, i.e. the area within which all register changes take place. Changes in vocal fold strain appeared similar in male and female subjects. Evidence for different strain patterns in covered and open singing is presented for female subjects: strain is higher in non-singers and (“incorrect”) open voice, lower in singers and (“correct”) covered voice for a given pitch area. Previous research on vocal fold length-changes and vocal registers is also summarized and critically assessed.