This text presents findings in the study of the sensory functions of aquatic mammals, with an emphasis on hearing, vision, and somatic senses. The book opens with a discussion of the anatomy and mechanics of the cetacean middle and inner ear and demonstrates what makes it particularly sensitive to high frequencies; it then focuses on vision in aquatic mammals: specifically, those with centrally-symmetric eye optics with a quasi-spherical lens and hemispheric eyecup. Finally, it concludes with a comparative analysis of sensory systems of aquatic mammals and terrestrial mammals.
1. Intruduction.- 1.1. General.- 1.2. Aquatic Mammals as Subjects of Experimental Studies.- 1.3. The Physical Properties of Water as a Sensory Medium.- 1.4. Psychophysical Measurement Procedures.- 2. Hearing in Cataceans.- 2.1. Ear Morphology.- 2.2. Auditory Evoked Potentials in Cetaceans.- 2.3. Evoked-Potential Procedures in Hearing Measurements.- 2.4. Hearing Sensitivity and Frequency Range.- 2.5. Temporal Resolution.- 2.6. Frequency Tuning.- 2.7. Sound-Intensity Discrimination.- 2.8. Directional Sensitivity, Spatial, and Binaural Hearing.- 2.9. Frequency-Temporal and Frequency-Spatial Interactions.- 2.10. Sound-Conduction Pathways.- 2.11. Central Representation of the Auditory System.- 2.12. Implements to Echolocation.- 2.13. Summary.- 3. Hearing in Pinnipeds and Sirenians.- 3.1. Hearing in Pinnipeds.- 3.2. Hearing in Sirenians.- 3.3. Summary.- 4. Vision in Aquatic Mammals.- 4.1. Vision in Cetaceans.- 4.2. Vision in Pinnipeds.- 4.3. Vision in Sirenians.- 4.4. Summary.- 5. Somatic Sense in Aquatic Mammals.- 5.1. Somatic Sense in Cetaceans.- 5.2. Somatic Sense in Pinnipeds.- 5.3. Summary.- References.