Previous work pointed to the neural and functional significance of infraslow neural oscillations below 1 Hz that can be detected and precisely located with fast functional magnetic resonance imaging (fMRI). While previous work demonstrated this significance for brain dynamics during very low-level sensory stimulation, we here provide the first evidence for the detectability and functional significance of infraslow oscillatory blood oxygenation level-dependent (BOLD) responses to auditory stimulation by the sociobiological relevant and more complex category of voices. Previous work pointed to a specific area of the mammalian auditory cortex (AC) that is sensitive to vocal signals as quantified by activation levels. Here we show, by using fast fMRI, that the human voice-sensitive AC prioritizes vocal signals not only in terms of activity level but also in terms of specific infraslow BOLD oscillations. We found unique sustained and transient oscillatory BOLD patterns in the AC for vocal signals. For transient oscillatory patterns, vocal signals showed faster peak oscillatory responses across all AC regions. Furthermore, we identified an exclusive sustained oscillatory component for vocal signals in the primary AC. Fast fMRI thus demonstrates the significance and richness of infraslow BOLD oscillations for neurocognitive mechanisms in social cognition as demonstrated here for the sociobiological relevance of voice processing.