Preface to v6

While not exactly a second edition, v6 contains more significant updates to the theory compared to the one that first appeared in September 2021 and its subsequent public versions on arXiv (v1–v5; https://arxiv.org/abs/2111.04338).

The most substantial update is the addition of two more supporting studies to the section about the time lens (§11.6.2). Although human-relevant curvature values are difficult to extract from these animal data (§11.6.4), the current total of five different studies helps to push the idea that the cochlea contains a time lens away from the realm of speculation. Still, the data appear to be clustered in two curvature ranges of the putative time lens, which may be difficult to accept without the interaction with auditory accommodation—itself a speculative idea, albeit completely in line with the system physiology and the precedent of accommodation in vision. The addition of more data points to the time lens curvature had a slight cascade effect on many of the quantitative predictions in this work, which were corrected accordingly. It also led to a correction of an error in the related formula of the octave stretch effect in §15.10.1. Unfortunately, this update produces an octave stretch effect prediction that is more limited and somewhat messier than in the previous editions, although still relevant. Throughout, the large-curvature time-lens estimates have been used, whereas the small-curvature estimates were no longer viable in most contexts. This is unlike the previous versions of the text, where the difference between the two curvatures informed us of the extreme values of the system curvature range.

Another major addition to this work is the summary, which aims to provide a briefer and lighter exposition to the ideas of the temporal auditory imaging theory and is more accessible than the technical abstract and long introductory chapters. The summary was constructed in a rather deductive manner, which rests on six points that were themselves gathered from the text (although without explicit reference to them later). Other changes are the additions of a couple dozen recent references (more than 1600 in total), a figure of the peripheral ear, and minor corrections to some figures and text.

Preface to v7

With the exception of a clearer presentation of the results of the experiments in §E, the changes in this version (v7) are all relatively minor: the usual correction of typos and references, as well as the inclusion of several new references from the past couple of years and a few ones that were overlooked before (notably, a mention of an imaging system in lizards with a parietal eye that is part of their pineal complex, the hypothesis that color vision in cephalopods is based on defocus, and the term “contrast sensitivity function” that is the correct visual equivalent to temporal modulation transfer function). However, to ease the future search and increase the visibility of this manuscript, this may be the final version that will appear on arXiv, for which I am grateful. Future updates may appear exclusively on the new web version to be found at http://www.hearingtheory.org.