<p>Impaired musical emotion perception is common in hearing loss, yet how reduced spectral audibility shapes cortical processing during emotion judgments remains unclear. Because alpha-band activity can index top-down control when sensory evidence is degraded, we examined whether spectral degradation increases the cognitive demand required to form stable affective judgments in music. Forty-eight healthy participants were divided into three groups: high-frequency hearing loss simulation (HF_sim), low-frequency hearing loss simulation (LF_sim), and normal hearing (NH). Participants rated the arousal and valence of filtered musical stimuli (happy, sad, neutral) during EEG recording. HF_sim showed dimension- and context-dependent alpha modulations. In the happy condition, arousal ratings and alpha power were comparable across groups, whereas valence judgments showed behavioral differences and late-stage alpha increases in HF_sim, consistent with reduced certainty when high-frequency cues supporting positive valence are degraded. In the sad condition, behavioral ratings were preserved, yet HF_sim showed sustained alpha increases during arousal judgments, suggesting compensatory inhibitory-gating processes that may support stable appraisal under degraded listening. Overall, spectral degradation appears to elicit compensatory cognitive processing: alpha power increases index higher demands for happy-valence with reduced HF cues, and compensatory gating that maintains sad low-arousal appraisal.</p>