Single-response variability of air and water caloric reactions.

The caloric response to either water or air stimulation has been compared in 10 normal subjects. The nystagmus signals have been analysed by digital signal processing. A statistical analysis of slow-phase velocity has been conducted. The variability of the single response appeared to be correlated with the level of response. Allowing for this correlation, no difference in variability could be detected when comparing both types of caloric stimulation. The consequences of error behavior for the current practice of calculating differences in labyrinthine sensitivity are discussed.