Long-term Effects of Chronic Otitis Media on Binaural Hearing in Children

Abstract

To determine the long-term effect of otitis media with effusion (OME) on binaural hearing in children. Longitudinal testing over a 4-year period following insertion of tympanic membrane grommets, employing clinical and normal control groups. Twenty-two children with a history of OME were tested before insertion of grommets and at 3 months and 1 year after surgery; 14, 11, and 8 of the children were followed up for 2, 3, and 4 years after surgery, respectively. An age-matched control group of 40 children was tested. The masking-level difference (MLD) paradigm was used to measure the ability of the binaural auditory system to aid the detection of a pure-tone signal presented in a random masking noise. Although the results indicated a significant improvement in the MLD with increasing time after middle ear surgery, the MLD remained significantly reduced even 2 years after hearing threshold correction. The MLDs of the OME group did not differ significantly from those of the control group when tested 3 years after middle ear surgery, even though a small proportion of subjects with a history of OME continued to have MLDs smaller than normal limits. In general, the results suggest a slow recovery of binaural function in children with OME after restoration of normal hearing thresholds.