Voice resemblance improved before call readiness did

A voice-conversion stage after synthesis

Seed-VC2 converted existing Supertonic speech with four, eight and twelve diffusion steps. The selected public audiobook references were thirty seconds long, but the upstream wrapper used only the first twenty-five seconds.

Do not optimize one score

A short English style/accent conversion reached speaker cosine around 0.880, yet local ASR recorded 100% word error on its six-word greeting. Timbre-only conversion preserved the greeting while improving resemblance. A successful conversion request therefore did not mean usable translated speech.

A separate female-reference test completed twelve conversions. Four-step timbre-only English measured cosine 0.861, about 1.119 seconds to the first complete chunk and zero ASR edits on six words. Spanish measured 0.803, 1.627 seconds and zero edits on five words. These tiny samples cannot establish production intelligibility.

Keep it experimental

The source study used demo narrators; no family voice is published here. Adding conversion to measured translation-stage timings yields only an arithmetic latency estimate. Real two-phone calls, consented enrollment, interruptions and network delay were not validated by these offline tests.

Evidence and publication boundary

This is an edited account of the recorded experiment. The linked archive is private; the methods, aggregate findings and limits are included above. Reference recordings, raw conversations, authentication material and workstation configuration are excluded.

• Source record 1
• Source record 2