Impaired speech learning, mental retardation and alterations of affectivity and behaviour may be the consequences of profound neonatal deafness. The authors emphasize the importance of detecting the newborns at audiological risk and screening the neonates in order to get an early diagnosis and treatment of the affection, at least within the first year of life, to avoid or reduce the consequences of hearing loss; then they describe the procedure commonly in use at present for neonatal hearing screening and a number of available different diagnostic tools (electrodermal audiometry, heart rate audiometry--with the possibility of autoregressive analysis--respiration audiometry, autoregressive analysis of EEG, acoustic impedance measurements with study of the acoustic reflex, auditory response cradle which is also named CRIB-O-GRAM).