Previous studies of spiral ganglion neuron electrophysiology have shown that specific parameters differ according to cochlear location, with apical neurons being distinctly different than basal neurons. In order to align these features more precisely along the tonotopic axis of the cochlea, we developed a novel spiral ganglion culture system in which positional information is retained. Patch clamp recordings made from neurons of known gangliotopic location revealed two basic firing pattern distributions. Membrane characteristics related to spike timing, such as accommodation, latency and onset tau, were distinctly heterogeneous, yet when averaged they were distributed in a graded manner along the length of the cochlea. Action potential threshold levels also displayed a wide range, the averages of which were distributed non-monotonically such that neurons with the greatest sensitivity were localized to the mid-regions of the ganglion. These studies shed new light on the complexity and sophistication of the intrinsic firing features of spiral ganglion neurons. Because timing-related elements are organized in an overall tonotopic manner it is hypothesized that they contribute to aspects of frequency-dependent acoustic processing. On the other hand, the different distribution of threshold levels, with the greatest sensitivity in the middle region of the tonotopic map, suggests that this neuronal parameter is regulated differently and, thus, may contribute a distinct realm of auditory sensory processing, such as intensity coding.