gemini-3.1-flash-tts-preview

Fined:

• fatal · currency — dropped the minus sign (7 of 7 transcripts)

→ we sent “A refund of -$0.99 was applied.”

→ it said “A refund of $0.99 was applied.”

• minor · dates — kept the value but never said “july”; a prompt fixes this (7 of 23 transcripts)

→ we sent “Your appointment is on 07/15/2026.”

→ it said “Your appointment is on seven fifteen, twenty twenty six.”

• minor · dates — kept the value but never said “january”; a prompt fixes this (8 of 23 transcripts)

→ we sent “Renewal falls on 1/1/2027.”

→ it said “Renewal falls on one one twenty twenty seven.”

• minor · dates — kept the value but never said “november”; a prompt fixes this (7 of 23 transcripts)

→ we sent “The policy started 11/30/2024.”

→ it said “The policy started eleven thirty, twenty twenty four.”

• minor · dates (international, ×0.4) — kept the value but never said “march”; a prompt fixes this (10 of 23 transcripts)

→ we sent “The order shipped on 2026-03-09.”

→ it said “The order shipped on twenty twenty six zero three zero nine.”

Token-billed: $1/1M text in, $20/1M audio out; Google states 25 audio tokens/sec (ai.google.dev/gemini-api/docs/pricing). At 900 chars/min of speech that is ~$33 per 1M chars; text-in adds ~$0.25, negligible.