Interaction of Voice Onset Time with Vocal Hyperfunction and Voice Quality

Featured Application This research article investigates whether the acoustic measure Voice Onset Time (VOT) can describe voicing features in patients with vocal hyperfunction. The main aim of the present work was to investigate whether vocal hyperfunction (VH), perceptual voice quality (VQ), gender, and phonetic environment influence Voice Onset Time (VOT). The investigated group consisted of 30 adults, including 19 women (X = 46.1 & PLUSMN; 13.7 years) and 11 men (X = 47.5 & PLUSMN; 11.0 years), who had either phonotraumatic vocal hyperfunction (PVH) and non-phonotraumatic vocal hyperfunction (NPVH). VQ was judged considering the overall severity of dysphonia (OS) and the subcharacteristics of roughness, breathiness, and strain. Phonetic variables such as vowel stress, syllable stress, and mode of speech task were analyzed. Four samples of syllables with plus vowel or diphthong were retrieved from CAPE-V sentences recordings. Acoustic analysis with Praat comprised VOT, mean fundamental frequency (fo), intensity (SPL dB(A)), and coefficient of variation of fundamental frequency (CV_fo %). VOT was significantly influenced by OS (p & LE; 0.001) but not by vocal VH condition (PVH versus NPVH) (p = 0.90). However, CV_fo was affected by the VH condition (p = 0.02). Gender effects were only found for mean fo (p & LE; 0.001) and SPL (p = 0.01). All VQ sub characteristics (OS, roughness, breathiness, and strain) correlated with VOT (p & LE; 0.001) and SPL (p & LE; 0.001) but not with fo. In summary, VOT was affected by voice quality, while it was not affected by vocal hyperfunction conditions. Therefore, VOT has the potential to objectively describe the onset of voicing in voice diagnostics, and may be one underlying objective characteristic of perceptual vocal quality.