Real production comparison: ElevenLabs vs PlayHT vs Azure TTS vs Cartesia for phone-quality voice AI

February 22, 2026

Here's something that caught my attention — after 18 months of running real phone calls with voice AI, the differences between TTS providers are clearer than ever. According to /u/AmbitiousInterest154, ElevenLabs delivers the most natural Italian voice, with excellent prosody and emotional range, but it’s pricey at scale and can glitch with longer sentences. Azure Neural TTS is reliable, with decent latency and good pricing, but sounds somewhat flat — more like a newsreader. PlayHT’s English quality is solid, but their Italian sounds off — unnatural stress and pauses, which might be okay if you're only using English. Cartesia shows promise with fast streaming and good English voice quality, but their Italian support is still limited. The real game-changer? The 'first 5 second detection rate' — how quickly callers realize they’re talking to AI. ElevenLabs hits around 15-20%, while Azure manages about 40%, which makes a huge difference for outbound calls. So, if you’re testing TTS for non-English use, pay close attention to real-world performance, not just demos. And get this — /u/AmbitiousInterest154 is curious about multilingual benchmarks and Italian transcription accuracy, too.

We’ve been running voice AI agents in production for 18+ months doing real phone calls (outbound lead qualification and inbound customer care).

During this time we’ve tested multiple TTS providers. Sharing our honest assessment because most “comparisons” online are either sponsored or based on 30-second demos, not thousands of hours of real phone conversations.

Important context: our use case is Italian-language phone calls over standard telephony (not VoIP, not in-app), which is a harder test than English because fewer models are optimized for it. We process audio at 16kHz.

ElevenLabs (currently in production): Best Italian voice quality by far. Prosody is natural, handles pauses well, emotional range is good. Latency for TTS generation is acceptable in our streaming setup. Downsides: pricing at scale gets expensive, and occasionally the voice “glitches” on certain phonemes. We’ve found that the voice stability is very dependent on how you structure your input text — short sentences work dramatically better than long ones.

Azure Neural TTS: Rock solid reliability, great latency, good pricing. Italian voices are okay but sound “flat” compared to ElevenLabs — like a newsreader vs a real person. For customer care this works fine. For outbound sales calls where you need warmth and persuasion, it wasn’t cutting it.

PlayHT: Tested their v2 API. English quality is impressive. Italian was noticeably worse — unnatural stress patterns, weird pauses between words. Might work for English-only deployments.

Cartesia: Very promising on latency (their streaming is genuinely fast). Voice quality for English is good. Italian support was limited when we tested. Worth watching.

The metric that matters most for us isn’t MOS score or any standard quality metric — it’s what we call “first 5 second detection rate,” meaning how often the person being called realizes they’re talking to AI within the first 5 seconds. With ElevenLabs we’re at roughly 15-20%. With Azure it was closer to 40%. That gap is massive for outbound conversion.

Has anyone done serious production testing of TTS providers for non-English languages?

Also very curious about Cartesia’s Italian/European language support — their architecture seems promising but I haven’t seen real multilingual benchmarks.

And for anyone using Deepgram or AssemblyAI on the STT side: how’s Italian transcription accuracy for you?

submitted by /u/AmbitiousInterest154
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