Editing Mean Opinion Score (section)

=== Limitations in Advanced Applications ===

As technology advances, particularly in AI-generated content, traditional MOS evaluation faces new challenges:

'''Ceiling Effects''': When synthetic speech approaches human quality, MOS becomes less discriminative, with most systems scoring in the 4.0-4.5 range where small differences may not be statistically significant.

'''Missing Dimensions''': MOS provides only an overall quality rating and may miss specific aspects like speaker similarity, emotional expression, or intelligibility of specific linguistic phenomena.

'''Cultural and Linguistic Bias''': MOS scores can vary based on evaluator demographics, language background, and cultural factors, potentially limiting generalizability across diverse user populations.