The aim of this study was to investigate the physical variations related to stress and the vocal expression of emotional state. One male and two female subjects produced the nonsense utterance “paappapaappa paappa” simulating five emotional states: neutral, surprise, sadness, enthusiasm, and anger. The main stress was on the italicized syllable. Fundamental frequency (f₀), sound pressure level (SPL), and intraoral pressure were measured. Glottal flow was estimated from the acoustic signal by means of an inverse filtering method (IAIF). All analyses concentrated on the first syllable and the primary stressed (third) syllable of the utterances. The expressions of emotional states differed from each other both in the f₀/SPL results and in the glottal waveforms. The simulation of emotional states also showed across-subject variation. The glottal waveform had expression-related variation independent of f₀and SPL.