The insterstimulus interval in caloric testing is defined as the time between the offset of the first irrigation and the onset of the next. The British Society of Audiology currently do not define an interstimulus interval as such, but recommend seven minutes between the onsets of consecutive irrigations. There is little evidence to support the use of seven minutes, and current guidelines are based on a compromise due to differences in literature and in interpretation of previous guidelines. Studies suggest and employ a range of interstimulus intervals, from three to fifteen minutes, with different reasoning for each. In clinical practice, and interstimulus interval that is too short or too long may have implications on the comfort of the patient or the clinical time taken to complete testing. An interstimulus interval that is too short also has the potential to contaminate the results of subsequent irrigations if nystagmus is still present.