[Mechanisms of sound reception and conduction in a dolphin].

Morphology of a lower jaw, model and behavioral experiments are discussed with the aim of exploring the mechanisms of sound reception and conduction to the dolphin's lower jaw canals taking into account known concepts of acoustics and a theory of group antennas. It is shown that the left and right row of mental foramens with the respective mandibular canal and tissues of the canals are forming the new outer ear and the new external auditory canal by which the sound (in frequency band of 0.1-160 kHz) is transmitted into the middle ear, in contrast to the dolphin's non-functional outer ear. This new external ear is created by nature as a receiving array of the traveling wave antenna located in the throat of the acoustical horn (a corresponding mandibular canal). The results give reason to assume the presence of similar new outer ear in Odontoceti.