To investigate whether the aetiology for hearing impairment in neonates with unilateral auditory neuropathy spectrum disorder could be explained by structural abnormalities such as cochlear nerve aplasia, a cerebellopontine angle tumour or another identifiable lesion.

In this prospective case series, 17 neonates were diagnosed with unilateral auditory neuropathy spectrum disorder on electrophysiological testing. Diagnostic audiology testing, including auditory brainstem response testing, was supplemented with computed tomography and/or magnetic resonance imaging.

Ten of the neonates (59 per cent) showed evidence for cochlear nerve aplasia. Of the remaining seven, four were shown to have another abnormality of the temporal bone on imaging. Only three neonates (18 per cent) were not diagnosed with cochlear nerve aplasia or another lesion. Three computed tomography scans were reported as normal, but subsequent magnetic resonance imaging revealed cochlear nerve aplasia.

Auditory neuropathy spectrum disorder as a unilateral condition mandates further investigation for a definitive diagnosis. This series demonstrates that most neonates with unilateral auditory neuropathy spectrum disorder had pathology as visualised on computed tomography and/or magnetic resonance imaging scans. Magnetic resonance imaging is an appropriate first-line imaging modality.

This study aimed to evaluate the effect of lengthening the transition duration of selected speech segments upon the perception of those segments in individuals with auditory dys-synchrony.

Thirty individuals with auditory dys-synchrony participated in the study, along with 30 age-matched normal hearing listeners. Eight consonant–vowel syllables were used as auditory stimuli. Two experiments were conducted. Experiment one measured the ‘just noticeable difference’ time: the smallest prolongation of the speech sound transition duration which was noticeable by the subject. In experiment two, speech sounds were modified by lengthening the transition duration by multiples of the just noticeable difference time, and subjects' speech identification scores for the modified speech sounds were assessed.

Subjects with auditory dys-synchrony demonstrated poor processing of temporal auditory information. Lengthening of speech sound transition duration improved these subjects' perception of both the placement and voicing features of the speech syllables used.

These results suggest that innovative speech processing strategies which enhance temporal cues may benefit individuals with auditory dys-synchrony.