Evaluation of temporal and suprasegmental auditory processing in patients with unilateral hearing loss

To determine the temporal order, resolution, and perception of prosody skills in Single-Sided Deafness (SSD) compared to an age- and sex-matched normal hearing group's same side ear and both ears.

This was a Case-Control study including 30 subjects with SSD, and age- and sex-matched 30 subjects with bilateral normal hearing (total of 60 subjects- mean age: 38.7 ± 11.6 years). The Montreal Cognitive Assessment (MoCA), Frequency Pattern Test (FPT), Duration Pattern Test (DPT), Random Gap Detection Test (RGDT), Evaluation of Motor Response Time and Emotional Prosody Assessment were performed on the clinically normal ear in the SSD group, the same side ear in the normal hearing group, and both ears of the normal hearing group (the SSD, MNH, and BNH groups, respectively).

Individuals with SSD had worse results in DPT (p < .001), gap detection at 0.5 kHz (p < .001), gap detection at 4 kHz (p < .001), and composite score (p < .001) than the BNH group. For reaction time measurements, the SSD group had slower performance scores than the BNH group for DPT (p < .001) and FPT (p < .001).

Poor temporal processing ability and reduced reaction times may help explain the difficulties in those with SSD in performing daily living activities such as speech understanding in noise and requires more processing efforts. However, there were no significant differences between the groups in frequency pattern performance and emotional prosody skills, supporting the claim that fundamental frequency is one of the most important measures of perception in emotional prosody. We demonstrated that unilateral hearing is adequate to analyze frequency patterns to aid in prosody perception. Analysis of reaction times in temporal processing and emotional prosody could provide different perspectives of auditory processing. Slower reaction time of SSD should be considered for habilitation purposes.