On-line computer methods were developed and evaluated for automated hearing testing with auditory brain stem responses (ABR). The system contained (1) a response recognition unit which recognized the presence or absence of an ABR response and (2) a threshold tracking unit which adjusted stimulus intensity and determined the ABR threshold. Two methods, one nontemplate (variance ratio) and one template (cross-correlation), were evaluated for response recognition while three threshold tracking methods were explored: clinical, Békésy, and PEST (parameter estimation by sequential testing). Both response recognition and threshold tracking units were evaluated by computer simulations for on-line operation using a standard set of experimentally recorded ABRs. The results indicated that while all the response recognition methods were reasonably accurate, their on-line use resulted in significant differences in test efficiency due to differences in tracking methods.