At 16 sites, repeat changes failed a shared sound group test in six SEEG patients and 16 fMRI adults

We tested if repeat changes distinguish source speech/song sounds from source nonvoice sounds. We removed total change size and sign. Separate public human studies supplied SEEG high-gamma activity and BOLD fMRI. Development used two patients and four MRI adults. A local code lock preceded tests in six other patients and 16 other adults. Ten fixed 16-site panels and five whole-sound folds gave one AUC per person. Mean AUCs were 0.53426 and 0.53728. Their 95% person Student limits were [0.46386, 0.60466] and [0.51726, 0.55731]. The shared Student, sign-flip, label-reference and interval rule failed, p=0.15625. Eight further MRI adults gave 0.51643 [0.49341, 0.53946]. All negative people and controls remain. Mean-response controls gave AUC near 0.95-0.97. They do not repair the failed test. An exact identity shows that scalar repeat gains can preserve stable response shape in normalized differences with no additive noise. A generated example gave AUC 0.99040; it was not fit to human outcomes. One shared clinical schedule also predicted labels. This is not a neural effect. The contribution is a fixed benchmark, a checked interpretation limit and a complete result record. Source selection, clinical coverage, acoustics, common schedules, separate cohorts and unequal measurement filters limit scope. No positive cross-modal neural claim or cause was established. The package gives code, source versions and terms, all predictions and results, figures and repeat steps. Original neural arrays remain external.

human neuroscience · SEEG · fMRI · auditory cortex · response variability · sound groups · negative result · repeat gain