Failure to recognize the presence of a hearing impairment in early childhood can severely harm the development of the child. A differentiation is made between sound conduction deafness and sensorineural.deafness. The former may be temporary or permanent. The latter may be inherited or acquired. Inherited sensorineural deafness occurs within the framework of syndromes, or may be monosymptomatic. Acquired sensorineural deafness may occur prenatally, perinatally or postnatally. A range of subjective and objective audiological tests is available, which, depending on the age and state of developmental of the child, can be used in combination. Cases of syndromal deafness are investigated on an interdisciplinary basis and involve the pediatrician, geneticist, laboratory physician and radiologist.