Cochlear morphometric and frequency data for mammals

Range Table - link
Organism Mammals
Reference Manoussaki D et al., The influence of cochlear shape on low-frequency hearing. Proc Natl Acad Sci U S A. 2008 Apr 22 105(16):6162-6. doi: 10.1073/pnas.0710037105 p.6164 table 1PubMed ID18413615
Primary Source See pointers to refs at right of table
Method Abstract: "Recently, a theory proposed that the spiral's graded curvature enhances the cochlea's mechanical response to low frequencies. This article provides a multispecies analysis of cochlear shape to test this theory and demonstrates that the ratio of the radii of curvature from the outermost and innermost turns of the cochlear spiral is a significant cochlear feature that correlates strongly with low-frequency hearing limits."
Comments P.6163 right column bottom paragraph: "Behavioral audiograms and morphometric data are listed in Table 1. The data are presented graphically in Figs. 2 and 3. All species included in the present dataset have generalist ears and thus typical mammalian hearing abilities that span seven to nine octaves and extend well into high frequencies and LFs (low-frequencies)." P.6165 right column top paragraph: "[Investigators] also note that BM (basilar membrane) apical width, or BM apical width/thickness ratio, given in Table 1, correlates no better than BM length times turns vs. LF hearing limit. This is consistent with the rather small variation across species of BM width on energy focusing in Eq. 5. Is cochlear size an important parameter for LF limits? [Their] calculations indicate that the radii ratio is important, and that the size is not important. This can be seen in two ways, by comparing cochleas of equal length but different ratios or similar ratios but different lengths. Cases for both appear in Table 1."
Entered by Uri M
ID 117125