The differential vulnerability of the inner ear end-organs to several external factors.

In a number of recently conducted animal studies, the effect of various external factors such as ototoxic substances, different types of noise and systemic disease on the different end-organs of the inner ear has been investigated. These studies are distinguished by the use of short latency vestibular evoked potentials (VsEPs) (to both linear and angular acceleration), an objective method for directly assessing the function of the different vestibular end-organs. In addition, the well known auditory brainstem response (ABR) was used to assess cochlear function. The studies are reviewed and it appears that the general pattern of effect is as follows: ABR (cochlea) is the most sensitive to the various external factors; angular VsEPs (semicircular canals) the least sensitive; linear VsEPs (otolith organs) intermediate between them.