Patients with moderate-to-severe unilateral conductive hearing loss (UCHL) can make use of binaural
difference cues when stimuli are presented at a high enough intensity to provide audibility in the affected ear.
Spatial hearing is essential for listening in complex environments and sound source localization
. Patients with UCHL have decreased access to binaural
difference cues, resulting in poorer spatial hearing abilities compared with listeners with normal hearing.
Twelve patients with moderate-to-severe UCHL, most due to atresia
(83.3%), and 12 age-matched controls with normal hearing bilaterally participated in this study. Outcome measures included: 1) spatial release from masking
, and 2) sound source localization
. Speech reception thresholds were measured with target speech (Pediatric AzBio sentences) presented at 0 degree and a two-talker masker that was either colocated with the target (0 degree) or spatially separated from the target (symmetrical, ±90 degrees). Spatial release from masking
was quantified as the difference between speech reception thresholds in these two conditions. Localization
ability in the horizontal plane was assessed in a 180 degree arc of 11 evenly-spaced loudspeakers. These two tasks were completed at 50 and 75 dB SPL.
Both children and adults with UCHL performed more poorly than controls when recognizing speech in a spatially separated masker or localizing sound; however, this group difference was larger at 50 than 75 dB SPL.
Patients with UCHL experience improved spatial hearing with the higher presentation level, suggesting that the auditory deprivation associated with a moderate-to-severe UCHL does not preclude exposure to—or use of—binaural