https://www.selleckchem.com/pr....oducts/plumbagin.htm
The current paper examined the impact of dysphonia on the bandwidth of the first two formants of vowels, and the relationship between the formant bandwidth and vowel intelligibility. Speaker participants of the study were 10 adult females with healthy voice and 10 adult females with dysphonic voice. Eleven vowels in American English were recorded in /h/-vowel-/d/ format. The vowels were presented to 10 native speakers of American English with normal hearing, who were asked to select a vowel they heard from a list of /h/-vowel-/d/ word