Shno Koiek1,2, Jens Bo Nielsen3, Harvey Dillon4,5, Christian Brandt1,2, Tobias Neher1,2
1Institute of Clinical Research, University of Southern Denmark, Odense, Denmark
2Research Unit for ORL – Head & Neck Surgery and Audiology, Odense University Hospital, Odense, Denmark; University of Southern Denmark, Odense, Denmark
3Hearing Systems, Department of Health Technology, Technical University of Denmark, Lyngby, Denmark
4Department of Linguistics, Macquarie University, Sydney, Australia
5Manchester Centre for Audiology and Deafness, The University of Manchester, Manchester, United Kingdom.

Several studies have reported negative long-term effects of early-childhood otitis media (OM) on the ability to exploit binaural information for segregating competing speech signals. Whether corresponding effects also manifest themselves at lower levels of auditory processing has not been investigated systematically. The aim of the current study was to investigate the long-term effects of OM on speech recognition in stationary noise or competing speech with or without binaural differences between the target and maskers. Another aim was to investigate the effects of the individual otologic history on these results. Children aged 6-13 years either with (N = 42) or without a history of OM (controls, N = 20) participated. For measurements in stationary noise, the target speech was presented from 0° and the masker from 90°. Speech reception thresholds (SRTs) were then measured with the stimuli presented either binaurally or monaurally to the ear opposite to the noise. For measurements with competing speech, binaural SRTs were measured with the target speech presented from 0° and two speech maskers presented from either 0° or ±90°. For each set of measurements, binaural advantage scores were also calculated. To investigate the influence of the individual otologic history, an index of overall OM severity (OMS) was derived based on OM onset age, overall OM duration, and time since the last OM episode from the children’s otologic records. The OM children showed poorer monaural and binaural SRTs in stationary noise as well as poorer binaural SRTs with speech maskers from ±90° compared to the controls. The binaural advantage scores were similar between the two groups. Consequently, the hearing deficits in noise in OM children appear to arise from lower levels of auditory system. After controlling for age, the defined OMS index was not a significant predictor of the hearing in noise abilities in OM children.