An investigation of vowel formant position and judgments of roughness

The purpose of this study was to investigate the importance of the first formant frequency position upon the perceptual judgment of vocal roughness. Vowel-like stimuli were synthesized using a laryngeal analog and vowel filters. The basic experimental variable in the study was the position of the center frequency of the first formant. The hypothesis upon which the study was generated was that the higher the first formant frequency the greater would be the judgments of roughness. The results supported the hypothesis. Those vowels produced with low first formant frequencies were judged as less rough than those with higher formant frequencies. Clinical interpretations from the study are drawn which state that diagnostic procedures should include high first formant vowels.