Lastly, they went on to further explore the driving forces behind the interaural time difference, specifically whether the process is simply the alignment of inputs that is processed by a coincidence detector, or whether the process is more complicated. Evidence from Franken, et al. shows that the processing is affected by inputs that precede the binaural signal, which would alter the functioning of voltage-gated sodium and potassium channels to shift the membrane potential of the neuron. Furthermore, the shift is dependent on the frequency tuning of each neuron, ultimately creating a more complex confluence and analysis of sound. Franken, et al.'s findings provide several pieces of evidence that contradict existing theories about binaural audition.