Sound translation into neural message at the first auditory synapse is of prime importance for providing organism with sound environment. Here, we compiled experimental features of the primary auditory neurons into a computational model, composed of two distinct compartments (i.e., afferent bouton and axon). Simulation of the model closely reproduces the whole biophysical properties of both excitatory post-synaptic currents and action potentials firing. This simple model provides a powerful tool to understand the synaptic disorders on the sound neural coding at the first auditory synapse.