Ear dominance for nonsense-syllable recognition ability in sensorineural hearing-impaired children: monaural versus binaural amplification.

The purpose of this investigation was to determine whether an auditory-deprivation/dominant-ear effect associated with nonalternating monaural amplification is present in children. Subjects were 35 children with bilateral symmetric, moderately severe to profound, sensorineural hearing impairment. Seventeen were fitted with nonalternating monaural amplification and 18 were fitted with binaural or alternating monaural amplification. Taped speech stimuli consisted of 20 nonsense syllables. The mean age at which subjects were fitted with amplification was 4.8 years for the monaural group and 4.9 years for the binaural group. The mean period between hearing-aid fitting and the initial test was 4.1 years for the monaural group vs. 3.4 years for the binaural group. The mean interval between the age at retest and the age at which the subject was fitted with amplification was 15.8 years for the monaural group and 13.9 years for the binaural group. Results revealed a significant difference in the mean interaural difference score (IDS) for nonsense-syllable recognition (NSR) at the initial test and at the retest between group A and group B. The results also revealed that the progression from initial test to retest in the IDS for NSR was 10.7 percent for the nonalternating monaurally fitted subjects as compared with -3.3 percent for the binaurally or alternating monaurally fitted subjects. Results are discussed in relation to the theories of auditory deprivation and ear dominance.