Most researchers argue that there is general agreement on the role of environmental and behavioral factors on the onset of the auditory exostoses. Accordingly, it can be considered an aquatic activity marker in bioarchaeological studies. In this paper, the prevalence of external auditory exostoses was examined between two prepottery Neolithic communities from Asikli Huyuk and Cayonu Tepesi in Anatolia. Both the etiology of the ear exostoses and the causative interactions between aquatic activities and the occurrence of this trait were discussed. Of 97 adult skulls (59 males, 38 females) from the Cayonu sample only 17 subjects (15 males and 2 females) showed this bony outgrowth with a prevalence of 17.52%. There is a strong male bias in lesion frequency. Among the 28 adult skulls that were examined from Asikli (11 males, 17 females), only one young male (3.57%) was affected with ear exostoses. This bony lesion is completely lacking in subadults (< 15 years) of both skeletal samples. (C) 2012 Elsevier Inc. All rights reserved.