The goal of this research is to devise automated methods of analyzing the Auditory Brainstem Response (ABR) when it is recorded using three orthogonal channels. The resulting 3-Channel Lissajous Trajectory (3-CLT) shows both linear and planar portions, which will be detected using algorithms tested under realistic conditions of background noise. The 3-CLT methodology is likely to be more sensitive to pathological changes in the auditory nervous system than is the ABR, though the ABR has had extensive use in audiology and neurology as a measure of brainstem normality or abnormality. The automated methods will be designed for microcomputers which are likely to be the basis for evoked response recording systems in the future. At least six companies now produce such systems, primarily for clinical use, but the ABR systems cannot record or analyze the 3-CLT at present, and reliable algorithms are not yet known for the otherwise complex and time-consuming analysis that the 3-CLT requires.