Persons with intellectual disabilities are at increased risk for hearing impairment. If left untreated such hearing impairments may aggravate the social and communicative problems of these persons. The aims of this study are to determine the prevalence of hearing impairment and to distinguish between peripheral and central part of detected hearing disorders in this population. During the German Special Olympics Summer Games 2006, 552 athletes with intellectual disabilities received a hearing screening which included otoscopy, measurement of otoacoustic emissions, and optionally tympanometry and pure tone audiometry (PTA) at 2 and 4 kHz. 20 athletes completed a test battery of discrimination thresholds for frequencies, tone amplitude modulation, and tone duration with both interaural and dichotic protocols. Of the 524 athletes who finished the screening, 76% passed and 24% failed it. 42% of the athletes were recommended to consult an otolaryngologist or an acoustician. Of the 99 athletes whose screening-based suspicion of a hearing loss was confirmed with a diagnostic PTA, 74 had a so far unrecognized hearing loss. All 20 athletes who received tests for central auditory processing had higher than normal thresholds for tone duration, 15 for amplitude modulation, and 14 of 19 for frequency discrimination in the dichotic protocol reflecting a considerable proportion of central auditory processing disorders in this population. The prevalence of hearing impairment and the proportion of undetected hearing impairments is high in this population. Therefore, special attention of professionals as well as regular hearing assessment and standard therapy programs are required for persons with intellectual disabilities.