The purpose of this study was to examine temporal resolution in normal hearing pre-school children. Word recognition was evaluated in quiet and in spectrally identical continuous and interrupted noise at signal-to-noise ratios (S/Ns) of 10, 0, and -10 dB. Sixteen children four to five years of age and eight adults participated. Performance decreased with decreasing S/N. At poorer S/Ns, participants demonstrated superior performance or a release from masking in the interrupted noise. Adults performed better than children, yet, the release from masking was equivalent. Collectively these findings are consistent with the notion that preschool children suffer from poorer processing efficiency rather than temporal resolution per se.

The present study investigated the question of whether, in healthy young listeners, increases in discrimination task difficulty will alter the amplitude of either the N1 or P2 components of the late auditory evoked potential (LAEP). Using a stimulus oddball procedure, listeners discriminated changes in the frequency of ongoing tonal stimuli. On different test runs, task difficulty was manipulated by decreasing the size of the frequency differences and/or adding competing speech babble to the nontest ear. Both stimulus procedures produced significant decreases in P2 amplitude but had no effects on N1 amplitudes. This finding of selective effects on later rather than earlier occurring components of the LAEP provides objective evidence that some forms of auditory processing are mediated at more central levels of the system.

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The purpose of this study was to investigate distortion product otoacoustic emissions (DPOAEs) and outer/middle ear status in 12 African American children with normal hearing and homozygous sickle cell disease (SCD) and age-, gender-, and ear-matched African American controls. C. R. Downs, A. Stuart, & D. Holbert (2000) reported that DPOAE amplitudes were significantly larger for children with SCD. Because the integrity of the middle ear system directly influences OAE characteristics, it was felt that concurrent investigation of DPOAE amplitudes and outer/middle ear function in children with SCD was warranted. DPOAEs were evoked by 13 primary-tone pairs with f2 frequencies ranging from 1000 to 4500 Hz. Outer/middle ear status was assessed with tympanometry through indices of peak compensated static acoustic admittance, tympanometric width, tympanometric peak pressure, ear canal volume, and middle ear resonance frequency. Tympanograms were recorded with probe-tone frequencies of 226 and 678 Hz. DPOAE amplitudes were significantly larger for children with SCD (p < .05). There were no group differences in any of the middle ear indices (p > .05). These findings suggest that increased DPOAE amplitudes for children with SCD cannot be attributed to differences in outer/middle ear function as assessed with tympanometry.