Middle ear disease is one of the most common childhood illnesses (Kokko 1974) and often results in hearing loss. This type of conductive hearing loss is endemic among Aboriginal children in particular. Between twenty-five and fifty percent of Aboriginal primary school age children are affected by hearing loss at any point in time (Quinn 1988). However, Aboriginal children's hearing loss is often not identified, in part because of ‘masking’ due to cultural differences. The awareness of possible hearing loss among non-Aboriginal children is usually prompted by children's behaviour. For example, the children don't follow directions and fail to answer questions. However, among Aboriginal children these behaviours may also be attributed to cultural differences in appropriate social behaviour (Harris 1980). Therefore, concern about possible hearing loss is less likely to emerge on the basis of the behaviour of Aboriginal children (Price 1981, Howard 1991). This means identification of Aboriginal children's hearing loss often occurs only if children are tested, usually as part of a hearing screening program. However, in some areas of the Northern Territory at least, the likelihood of Aboriginal student's hearing being screened has actually diminished in recent years.