of noise leads to an excess release of glutamate at the IHC synapse. This
excess of glutamate induces excitotoxicity: first a swelling, then a disruption
of the postsynaptic ending. The synapse between the IHC and the auditory
nerveno longer functions (sudden deafness).
Because of neural plasticity, there may be regrowth of the dendritic ending and thus repair of the synapse, resulting in a functional recovery.
However, in the case of repetitive injuries, the neurone itself may die (see: delayed phase).