Hoc alterum auditus organi ossiculum est: Ear Ossicles in Physical Anthropology

Abstract

In spite of the importance of auditory ossicles in anthropological studies, very little attention has been paid to these bones, which are only rarely recovered in archaeological excavations and in osteological collections. In this paper, we attempt to review some studies that started in the 1960 from when we first collected and prepared ossicles from the early Egyptian osteological collection of Giovanni Marro in Turin (Italy). We attempt to delineate the potential of ear bones in the study of man. In a few cases, archaeological ossicles were discussed in connection with some forms of pathology. Other studies examined the phylogeny of primates based on auditory ossicles. The function of the ossicles is to transmit sound waves to the cochlear endolymph. The energy transmitted through the ossicles is conserved by the action of two levers, which convert the relatively wide and low-energy movements of the hammer into smaller high-energy movements of the stirrup. It is a matter of argument whether the different proportions of the ossicles may imply variations in auditory perception in primates, including man. While the hammer of modern humans and that of the great apes show similar absolute sizes, nevertheless, the ape manubrium is appreciably greater than that of man. This difference, combined with stirrup proportions, causes a strong “low-gear” effect in apes and, as a consequence, probably a different auditory acuity. Although only a few fossil Neanderthal auditory ossicles are known, it may be, nevertheless, of interest studying the ossicles from the viewpoint of vibration transfer impedance function. The methodology may also be appropriate to study the few Australopithecine ossicles that are known. It is a matter of question whether the ossicles may have a meaning in distinguishing human populations; nevertheless, at least a case of clear distinction between human population has been achieved as in the case of Antinoe Roman–Egyptians.