Abstract 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.