Vibroacoustic Stimulation and Auditory Acuity in Preterm Infants

Abstract

Vibroacoustic stimulation (VAS) is widely accepted as a simple and inexpensive adjunctive antenatal test for fetal well-being. However, possible adverse effects of VAS on auditory acuity are not completely known and are of concern, especially for infants delivered prematurely. The purpose of our study was to evaluate neonatal hearing with the brain stem auditory evoked response (BAER) in 33 preterm neonates exposed to acoustic stimulation in utero and to compare the results with those of 33 preterm neonates who were not exposed to acoustic stimulation. Of the 33 exposed neonates, four had abnormal BAER results, indicating an apparent hearing loss. In three of four cases, an infectious etiology was found, suggesting a lack of association between antenatal VAS and hearing loss. By comparison, of the 33 preterm infants not exposed to VAS antenatally (control group), one infant had an abnormal BAER result and was subsequently diagnosed to have suffered a congenital hearing loss.

Thus, the risk of acoustic trauma from exposure to antenatal VAS appears to be minimal, with no statistically significant differences between the abnormal neonatal BAER results in the treated and control groups (P = 0.071). A more plausible explanation for preterm neonatal hearing loss is infection.

Key Words:

• Hearing testing for the premature
• Infant