Construction of a practical and inexpensive air stimulator for caloric vestibular testing.

An inexpensive and practical method for delivering air into the aural canal at a selected stable temperature is described. A water-air heat exchanger utilizing the external circulation of a constant-temperature water bath brings the temperature of the air stream to a chosen value. Measurements indicate stable air outflow temperatures are maintained when proper nozzle design and air flow rates are employed. The apparatus is easy to construct and has proven convenient and effective when used in the clinical vestibular laboratory.