Cartesia Sonic vs Speechless

Cartesia Sonic is a text-to-speech model for real-time voice applications, available through the web and an API. It has sub-90ms latency and supports 44 languages. Sonic can interpret emotional subtext and add non-verbal expressions such as laughter to transcripts. Its localization feature carries emotion, tone, and speaker identity into another language, while custom pronunciation dictionaries let users set how proper nouns and domain terms are spoken. For voice agents, Managed Agents combine Ink-2 speech-to-text, a selected LLM, and Sonic-3.6 text-to-speech, with turn-taking and interruption handling. Phone connectivity can use Cartesia-provisioned numbers, imported Twilio numbers, or a carrier over SIP. Cartesia lists HIPAA compliance, SOC 2 Type 2, GDPR, and PCI. It says Sonic can be deployed on-premise, in a customer VPC on AWS, GCP, or Azure, or through OEM licensing. A free plan includes 20K credits per month and two concurrent text-to-speech requests. Paid plans start at $5/mo; higher tiers raise credit allowances and list capabilities including organizations and priority support.

Speechless has no write-up on Specifiction yet; its figures are above.