Amplitude Modulation Detection in Children with a History of Temporary Conductive Hearing Loss Remains Impaired for Years After Restoration of Normal Hearing.

Otitis media with effusion (OME) is considered a form of relative sensory deprivation that often occurs during a critical period of language acquisition in children. Animal studies have demonstrated that hearing loss during early development can impair behavioral sensitivity to amplitude modulation (AM), critical for speech understanding, even after restoration of normal hearing thresholds. AM detection in humans with a history of OME-associated conductive hearing loss (CHL) has not been previously investigated. Our objective was to determine whether OME-associated CHL in children ages 6 months to 3 years results in deficits in AM detection in later childhood, after restoration of normal audiometric thresholds. Children ages 4 to 7 years with and without a history of OME-associated CHL participated in an AM detection two-alternative forced-choice task at 8 and 64 Hz modulation frequencies using a noise carrier signal and an interactive touch screen interface. Thirty-four subjects were studied (17 with a history of OME-related CHL and 17 without). Modulation detection thresholds improved with age and were slightly lower (more sensitive) for the 64 Hz modulation frequency for both groups. Modulation detection thresholds of children with a history of OME-associated CHL were higher than control thresholds at 5 years, but corrected to expected levels between ages 6-7. OME-associated CHL results in impaired AM detection, even when measured years after restoration of normal audiometric thresholds. Future studies may shed light on implications for speech and language development and academic success for children affected by OME and associated conductive hearing loss.