Ksenia Lysikova

Collapse, Not Invariance: Diagnosing Auxiliary Objectives in Speech Anti-Spoofing

Speech anti-spoofing countermeasures degrade when the generator, codec or channel changes, and a common remedy is an auxiliary objective that shapes the embedding space; whether it does is invisible to EER, a pure ranking metric. We compare seven such objectives with cross-entropy over 113 runs on five corpora, AASIST3...