Influence of Loudness, Pitch, Vowel, and Voice Condition on Supraglottic Tissue Displacement in Female Participants

Purpose: The present study aims at exploring the effect of pitch, loudness, vowel, and voice condition on supraglottic activity among female participants with voice disorders and among female participants with normal voices. Methods: Forty-four volunteers were recruited. Inclusion criteria for the dysphonic group were: 1) age between 20 and 50 years, 2) reporting at least 1 year-long history of voice problems, 3) moderate or severe dysphonia. Inclusion criteria for normal-voice group were: 1) age between 20 and 50 years, 2) no history of voice problems during at least one year prior to enrollment in the study, and 3) perceptually normal voice. Flexible and rigid laryngeal endoscopic examinations were conducted to assess supraglottic activity during speech-based phonatory tasks. Two laryngologists (blinded judges) were asked to assess laryngoscopic video samples using a visual analog scale. They assessed 4 laryngoscopic variables: medial laryngeal compression, anterior-posterior laryngeal compression, vertical laryngeal position (VLP), and pharyngeal compression. Groups, loudness levels, and pitch were compared. Results: Degree of loudness, pitch, and type of vowel were significantly linked to higher scores on most supraglottic activity measures. No significant differences between dysphonic and normal participants were found on any laryngoscopic dependent variables, except for VLP in vowel [u:]. Conclusion: Degree of supraglottic activity should not be necessarily greater in female patients with functional dysphonia compared to normal-voice female participants. Loudness level, pitch, and vowel have a clear impact on the degree of tissue displacement of supraglottic structures in both normal and people with voice disorders. Thus, loudness, pitch, and vowel should be controlled when performing laryngoscopic examination in both clinic and research; otherwise conclusions may not be completely reliable.