Binaural masking level differences in infants with and without otitis media with effusion.

The binaural masking level difference (MLD) was measured in two groups of infants (aged 7-10 months) who either had or did not have a documented history of otitis media with effusion (OME). Subjects were trained to detect a 500 Hz signal (either in or out-of-phase between the ears) against an in-phase, narrow band noise masker centred at 500 Hz. Non-OME infants had elevated masked thresholds and reduced MLDs compared with normal-hearing older (7-12 years) children and adults (20-27 years). OME infants also had elevated masked thresholds and reduced MLDs but, in contrast to studies using older subjects, their results were similar to those of the non-OME infants. These results suggest that, during at least the first year of life, infants are disadvantaged compared with adults or children when listening in noisy environments. They also suggest that OME does not further compromise infants' ability to detect sounds in those environments.