During this period, research converged on creating detailed ultrastructural maps of the Organ of Corti through refined surface preparation and phase-contrast electron microscopy, enabling precise morphology during cochlear development. The field adopted a cross-species developmental framework, using embryonic to postnatal stages to describe maturation of the cochlea and labyrinth. The mouse emerged as a dominant model for ontogeny studies, and early functional assessments via neonatal scalp potentials began linking anatomy to hearing function, informing developmental neurophysiology and pediatric audiology. Historical Significance: The era's landmark developments included establishing a high-resolution ultrastructural view of the Organ of Corti, which anchored decades of morphology and developmental studies. The 1971 inner ear ontogeny work introduced a comprehensive timeline and cemented the mouse as a standard model for cochlear development, enabling broad genetic and developmental inquiries. Cross-species embryologic correlations and early functional measures from scalp potentials provided a unifying framework for vertebrate audition and pediatric neurophysiology.