[Methods, value and limits of prenatal hearing diagnosis]

An intrauterine sound test was developed for monitoring prenatal hearing disorders and evaluated concerning its efficacy and practical feasibility. The procedure is based on the fetesto capacity react upon exogenous sound stimulation. An acoustic stimulation was achieved by a noise generator placed directly on the maternal abdomen in the proximity of the fetal ear. Successful stimulation was monitored by sonographic means expressed as fetal child movements in 447 pregnant women at the end of the 26th to the 37th week of gestation. The most favourable time for an intrauterine hearing test is between the 30th and 32nd week of gestation. The quantity of amniotic liquor, placental location and pathological pregnancies influences the test results. Efficiency and limits of prenatal hearing diagnostics are discussed.