Early intracranial recordings of the auditory nerve, conducted by Møller et al. in the 1980s, explored how the nerve encodes simple sounds, such as clicks or tone bursts. We aimed to extend this work by investigating human auditory nerve responses to clicks, tone bursts, and phonemes, sounds crucial for speech perception. Our study focused on the relative importance of temporal fine structure and temporal envelope. Recordings of auditory nerve electrical activity were performed at the University Hospital of Reims on patients undergoing microvascular decompression surgery (NCT03552224) for trigeminal neuralgia or hemifacial spasm. This approach provided access to the human auditory nerve. Both normal-hearing and high-frequency hearing loss patients participated. Stimuli were delivered in a closed field (Etymotic ER1) and the auditory nerve activity was measured using a ball electrode (Ø1.6 mm, Inomed) connected to a Grass P511 amplifier. The generation and acquisition of the signals were entirely processed by a NI-PXI 4461 device controlled by a LabVIEW interface (National Instruments). In response to low-frequency tone bursts, the electrical signal recorded in normal hearing subjects clearly demonstrated phase-locked activity with the fine structure of the stimulus. The synchronization index calculated from a Fourier analysis of the nerve response was maximal at 700 Hz and declined progressively toward higher frequencies. Beyond 2 kHz, no phase-locked response could be observed. Surprisingly, a robust phase-locked response was observed in subjects in the 500-1000 Hz range even in cases of hearing loss up to 60-70 dB SPL. Phonemes (/o/, /u/, /i/, /y/ vowels and /du/, /bu/, /di/, /bi/ syllables) were delivered at 70 dB SPL in quiet or noisy environments. Our results also revealed a remarkable preservation of neural responses reflecting temporal fine structure in both normal and hearing-impaired patients. However, responses related to the temporal envelope were significantly reduced in those with hearing loss. This suggests that the basal region of the cochlea, which is often affected in hearing loss, plays a key role in processing the temporal envelope of sound. Intracranial recordings offer a promising way to study how the human auditory nerve encodes complex sounds. This technique has the potential to significantly improve our understanding of how hearing loss disrupts speech processing at the neural level.