OBJECTIVES/HYPOTHESIS: The goal of this study was to investigate the relationship between respiratory discomfort and voice measures, including perceived vocal effort and selected acoustic parameters. A secondary aim was to examine whether threat appraisal-measured as susceptibility to experience fear of suffocation-modulated these relationships. We hypothesized that greater dyspnea would predict worse voice outcomes, especially in speakers with greater fear susceptibility. STUDY DESIGN: Repeated measures study. METHODS: Fifty-eight healthy females were submitted to various levels of respiratory discomfort through rounds of breath-holding while they rated their perceived dyspnea. Participants performed a phonation task-in a comfortable and a loud voice-immediately after each breath hold and rated their perceived vocal effort and fear of suffocation. Smoothed cepstral peak prominence (CPPS), harmonics-to-noise ratio (HNR), mean fundamental frequency (mean F RESULTS: In the vocal effort models for comfortable and loud phonation, dyspnea was a significant predictor (P <
0.0001) and interacted significantly with fear susceptibility (P <
0.0001). In the comfortable condition, dyspnea was also found to be a significant predictor for CPPS (P = 0.0014) and mean F CONCLUSIONS: The relationships between respiratory discomfort and voice were influenced by fear, suggesting that sensory and affective mechanisms interact when impacting voice production and vocal effort perception. Future studies could investigate whether similar interactions may impact laryngeal function in voice and upper airway disorders.