Percentage of spectral classifiers and missing-F0 classifiers among the three musical competence groups. In Panels a and b, assignment is based on the Auditory Ambiguity Test (AAT) score. In Panels c and d, assignment is based on the guessing-corrected F0-prevalence value. The criteria for group assignment were, for Panels a and c, AAT score or F0-prevalence value either up to or above 50 (liberal criterion) and, for Panels b and d, AAT score or F0-prevalence value either below 25 or above 75 (stricter criterion). non-mus. = nonmusicians.