Anthropogenic noise may be a major source of habitat degradation for cetaceans. To assess and mitigate the effects of noise pollution on marine mammals, we need information on how and what they hear. Although hearing in odontocetes, or toothed whales, is well studied, few data are available for mysticetes, or baleen whales. Behavioural and electrophysiological hearing tests are presently impractical for mysticetes, but biomechanical, structural modelling provides hearing estimates based on auditory system anatomy. In this research, three-dimensional models were produced for minke Balaenoptera acutorostrata, blue Balaenoptera musculus, and humpback Balaenoptera novaeangliae whale inner ears from CT scans and histology to measure key features for estimating hearing ranges, e.g., basilar membrane thickness-to-width ratios. Full head reconstructions were also produced for minke whales based on head CT images and dissections.