Abstract
The spiral organs from the cochleae of twelve guinea-pigs were examined by phase contrast microscopy after micro-dissection and preparation by the surface specimen technique. The length of each section of the spiral organ was measured, and the number of cells in the first row of outer hair cells counted. Ratios between the number of cells in the first row of outer hair cells and the number of inner hair cells in a set distance were calculated at various points along the length of the spiral organ. These ratios were found to vary as a function of distance along the spiral organ. The data were used to construct a standard cochleogram which varied along its length according to the observed changes in the hair cell ratio