Perceptual Reorganization of Tinnitus Lateralization: A Clinical Marker of Multimodal Neuromodulation-Induced Plasticity

Background/Objectives: Tinnitus lateralization, a perceptual characteristic often neglected in clinical assessment, may reflect underlying auditory plasticity. This study aimed to investigate whether changes in tinnitus lateralization following a multimodal neuromodulation protocol are associated with improved clinical outcomes, particularly regarding tinnitus severity and discomfort. Methods: A retrospective interventional study was conducted with 104 adults diagnosed with chronic tinnitus. All participants underwent a combined protocol involving transcutaneous auricular vagus nerve stimulation (taVNS), cervical transcutaneous electrical nerve stimulation (TENS), and photobiomodulation (PBM) targeting auditory pathways. Clinical assessments included the Tinnitus Handicap Inventory (THI), Visual Analog Scales (VAS) for loudness and discomfort, and lateralization reports before and after treatment. Lateralization patterns were categorized and compared using ANOVA and Kruskal–Wallis tests. Linear models explored demographic and clinical predictors of symptom change. Results: Substantial changes in lateralization were observed post-treatment. Participants who shifted from bilateral to unilateral tinnitus or from unilateral to non-perception showed the greatest symptom reductions (p < 0.001). The Bilateral → Unilateral group presented the most marked THI reduction (−20.82 ± 7.12), while minimal changes were observed in the Bilateral → Bilateral group. Loudness and discomfort improvements followed similar trends. No significant influence of age or sex on clinical response was identified, whereas longer tinnitus duration showed a modest positive association with symptom improvement. Conclusions: Perceptual reorganization of tinnitus lateralization may serve as a clinical marker of response to neuromodulation. Tracking lateralization could provide a simple, cost-effective adjunct to outcome monitoring in tinnitus management.