Electro-optic response properties of a set of HAN cells have been investigated. In particular the transmission variation with applied voltage and the relationship between response time and electrical field have been atudied. The birefringence as a function of applied voltage and turn-on time is worked out. The experimental results are analyzed in terms of the linear-response theory. The results of the response time of the HAN cells are in agreement with the theoretical predictions derived from theory. The results reported point to the possibility of liquid crystal devices with improved response time.