The development of fetal hearing

The developmental origins of the ability to hear have been the subject of much debate and speculation. Since time immemorial, there has been much anecdotal evidence that the fetus responds to sound. In contrast, until the late 19th Century, scientific evidence and opinion held that the newborn was deaf and only developed the ability to hear in the first weeks after birth. At the beginning of the 20th Century the prevailing scientific and clinical view changed and it was accepted that the newborn was able to hear at birth. This led to much speculation about, and limited experimental study of, when the individual first started to hear. Detailed study of the ontogency of auditory abilities had to wait until the 1980’s when scientific opinion regarding the abilities of the newborn changed and the ultrasound technology with which to observe the fetus in utero became widely available. Research thus commenced in earnest to investigate the response of the fetus to sound. Despite this increased interest in fetal hearing, experimental studies have concentrated upon the responsiveness to sound in late pregnancy and not on the developmental origine of auditory abilities. It is the aim of this review to examine the ontogenesis of hearing in the fetus.