What results from long-term asymmetrical hearing loss regarding auditory function?

Long-term asymmetrical hearing loss can significantly affect auditory processing and overall auditory localization abilities. When one ear has better hearing than the other, the brain struggles to fuse the inputs from both ears effectively, leading to poor binaural fusion. This phenomenon refers to the brain's difficulty in integrating sound information received from each ear when there is a disparity in hearing ability.

Poor binaural fusion can result in challenges in understanding speech, particularly in noisy environments, as the listener may miss crucial cues that are normally processed through both ears working together. This often leads to a sense of disorientation in auditory space and can impact communication skills.

In contrast, the head shadow effect is a natural phenomenon where sounds are blocked or diminished by the head itself, essentially affecting sound localization rather than the fusion aspect, which is more about brain processing. CROS fitting would provide a way to address the imbalance in hearing between ears, while standard BTE (Behind-The-Ear) hearing aids might not specifically target the issues arising from asymmetrical hearing loss in terms of binaural processing and fusion. Therefore, poor binaural fusion is the direct outcome of long-term asymmetrical hearing loss, making it the correct answer.