Palatal myoclonus

Palatal myoclonus is a rapid spasm of the palatal (roof of the mouth) muscles, which results in clicking or popping in the ear. Chronic clonus is often due to lesions of the central tegmental tract (which connects the red nucleus to the ipsilateral inferior olivary nucleus). Uniquely, the clicking noise does not subside when the patient sleeps.

When associated with eye movements, it is known as oculopalatal myoclonus

General references

 * http://www.tchain.com/otoneurology/disorders/central/opm.html