Symmetry of tympanometric measurements and transient evoked otoacoustic emissions in neonates

PURPOSE:

to determine the occurrence of symmetry ≥ 70% between the ears, comparing the results of 226- and 1000-Hz tympanograms with otoacoustic emissions in neonates.

METHODS:

thirty-nine neonates (20 female and 19 male) were evaluated at an average age of 60 hours. Each newborn underwent 226- and 1000-Hz probe tone tympanometry and evaluation of the transient-evoked otoacoustic emissions in both ears. The results were subjected to statistical tests.

RESULTS:

occurrence of symmetry < 70% was observed in otoacoustic emissions for 74.4% of the neonates. Tympanometry produced a greater occurrence of symmetry ≥ 70% for both the 226- and 1000-Hz probe tones (76.9% and 84.6%, respectively). With regard to gender and ear, the differences in each test were not significant, although greater otoacoustic emission amplitude was observed for the right ear.

CONCLUSION:

the results suggest symmetry in the auditory system in its most peripheral portion, and asymmetries begin to occur from the cochlea.

Spontaneous otoacoustic emissions; Acoustic Impedance Tests; Newborn; Audiology