This is a Phase I proposal to develop stimuli and recording techniques for auditory brainstem hearing tests (ABR) that will be sensitive to low-frequency auditory thresholds. Currently, ABR tests using clicks or low-frequency tone pips have difficulty in reflecting low-frequency thresholds. The investigator will use a specially designed low-frequency stimulus to evoke the ABR, in combination with a high-frequency masker to eliminate the confounding contributions of the high-frequency fibers. The investigator proposes to test this technique in both normal-hearing adults and adults with high-frequency hearing loss in this phase of the project.