One approach to the problem of specifying the contribution of the primary auditory cortex to auditory perception has been based on single-neuron recording techniques in animals. These experiments measure the response rates of individual neural elements to parametric variations in 1 or more stimulus dimensions. The patterns of response rates and response failures revealed by these manipulations are quantitative descriptions of the form and fidelity of the cortex's representation of those stimulus dimensions. This strategy has been used to advantage in studies of the cortical representation of the spectral content of auditory events, the spatial location of a sound, and the time structure of sounds. The data constitute new links between neural coding and behavioral performance in normal and impaired listeners.