---
title: "What Is Speech-to-Speech AI"
url: https://stacklist.com/card/ac999065-973d-4f0f-b6ac-8d6e3f4ddac9
source_url: "https://synthesys.io/speech-to-speech/"
stack: https://stacklist.com/c/technology/stack/e7c8dcca-958f-41a2-8752-c32180a0af54
summary: "Synthesys speech-to-speech AI is a voice conversion technology that re-voices existing audio recordings through a different speaker while preserving the original timing, emotion, and intonation. The page compares speech-to-speech with voice cloning and text-to-speech, highlighting support for 140+ languages and use cases across marketing, podcasting, e-learning, and accessibility."
tags: "speech-to-speech, voice-conversion, ai-voice, text-to-speech, voice-cloning, multilingual, synthesys"
key_entities: "Synthesys (organization), Speech-to-Speech AI (technology), Voice Cloning (technology), Text-to-Speech (technology), The Coca-Cola Company (organization), TCS (organization), Yahoo (organization), Jetex (organization), London (location), AI Dubbing (concept)"
classification: "reference"
content_hash: "sha256:925c0ae1c7ecf71fb6ed2157a4d18ae54d4f6ee731d6c2a29ace19ebc46749d7"
acp_version: "0.2"
token_counts_approximate: 2718
visibility: public
agent_accessible: true
status: "final"
---

# What Is Speech-to-Speech AI

Synthesys Speech-to-Speech Speech to Speech Any voice, any accent, anytime Convert any recorded voice into any other voice in seconds. Synthesys speech-to-speech preserves the timing, emotion, and intonation of your source audio, then re-synthesises that performance through the target voice you choose. Start Converting Voices Hear Voice Samples Used across marketing, podcasting, e-learning, and accessibility teams to turn one recorded performance into every voice they need — in 140+ languages, without re-booking talent. Source recording Voice Converted 00:12 Target voice: Rachel Same performance Empower Your Voice With Synthesys Speech-to-Speech AI : Any Voice, Any Accent, Anytime Instantly transform your voice into another voice or accent. Achieve a natural-sounding voice in under five minutes with Synthesys speech-to-speech AI. Trusted by global enterprise teams The Coca-Cola Company tcs yahoo! Heat and Control AT&S Jetex The Coca-Cola Company tcs yahoo! Heat and Control AT&S Jetex What is speech-to-speech AI? Speech-to-speech AI is voice conversion technology that takes an existing audio recording and re-voices it through a different speaker, while preserving the timing, prosody, emotion, and intonation of the original performance. Unlike text-to-speech , which generates audio from written text, speech-to-speech starts from your existing recording. The output sounds like the target speaker delivered the line themselves, with the source actor's timing intact. Synthesys speech-to-speech sits inside a wider voice production studio that also handles voice cloning , AI dubbing , and AI avatar video . That means one source recording can become a localised voiceover, a multi-language ad campaign, or a lip-synced avatar video without leaving the dashboard. Synthesys · AI Video Agent · Multi-model orchestration · London since 2020 Unlock your passport to sound exactly like anyone with Synthesys speech-to-speech AI What do you do when the voice you have selected doesn't sound exactly as you want? Do you keep regenerating different voices? This would be exhausting. With Synthesys speech-to-speech AI, however, you can use the exact voice you want when you want. You can use your own voice or choose one of our natural-sounding voices. Morph your voice into any accent in six clicks, and share your message with the world. Carry the performance Preserve emotion and timing Breath, pauses, emphasis, and pitch contours from your source recording carry into the output voice. The new speaker delivers the line with the same intent. Change the speaker Any target voice in seconds Pick from the studio library, or convert through a voice you have cloned yourself. Same source clip, different speaker per render. Iterate without re-recording. Ship in any language 140+ languages, one recording Retarget your source delivery to native voices in over 140 languages. Localise an entire campaign without re-booking voice talent per market. Convert Your First Voice Speech-to-Speech vs Voice Cloning vs Text-to-Speech Three related voice technologies inside Synthesys AI Studio. Each solves a different production problem. Pick by starting input. Property Speech-to-Speech Voice Cloning Text-to-Speech Starts from Existing audio recording 10-second voice sample Written text Preserves source timing and emotion Yes No (generates fresh delivery) No (generates fresh delivery) Changes the speaker Yes, to any target voice Captures one new voice Reads in chosen library voice Best for Re-voicing existing takes, ADR, localisation Building a reusable brand voice Generating voiceover from scripts Multilingual 140+ languages 140+ languages 140+ languages Typical use case Podcast pickups, dubbing, accessibility Founder voice for marketing Course narration, explainer videos Most teams use the three together. Clone a brand voice once, then run every new recorded take through speech-to-speech into that cloned voice. Use text-to-speech for fresh scripts where there is no source recording to convert. Why Use Synthesys Studio's AI Speech-to-Speech Generator? Four reasons teams choose Synthesys speech-to-speech over standalone voice tools. 1 Versatility Change your voice into any accent with our 14+ premium voices, catering to diverse communication needs. 2 Customisation Tailor your message precisely using advanced voice modulation controls and fine-tune settings, ensuring clarity, authenticity, and resonance with your audience. 3 Accessibility Empower users with speech disabilities, such as cerebral palsy or muscular dystrophy, to communicate effectively through natural voice generation. 4 Efficiency Enjoy fast rendering times, unlimited audio renders, and an intuitive user interface, maximising productivity, user engagement, and global reach in various applications like content creation, public announcements, or professional services. Synthesys AI Voices Speech to Speech A sample of the speech-to-speech target voices most teams reach for first. The wider library covers 400+ voices across 140+ languages, plus any voice you clone yourself. 🇺🇸 Rachel US English Warm narration voice, calibrated for podcast hosts, audiobook ADR, and explainer voiceover. 🇺🇸 Domi US English Confident, mid-tempo delivery suited to product ads, brand promos, and creator UGC content. 🇺🇸 Drew US English Authoritative male voice for training narration, financial content, and corporate explainer. 🇬🇧 Clyde British English Deep British voice for documentary narration, premium brand storytelling, and audiobook fiction. 🇬🇧 Alice British English Polished British female voice for e-learning narration, corporate training, and audiobook reads. Browse 400+ voices in the studio → How To Use Synthesys Studio's AI Speech-to-Speech Generator Ready to transform your voice? Follow these four steps. 01 Begin Your Project Log into your Synthesys account and initiate your project by clicking on the "AI Voices" button. 02 Upload your audio sample Upload your voice recording or simply speak directly into the platform. Synthesys automatically understands your speech and converts it to your desired accent. We recommend that you upload MP3 files for best results. 03 Choose your voice Choose the perfect voice to match your target audience. 04 Save and download Save your audio project and download it in MP3 format for easy sharing and use across various platforms. Speech-to-Speech Use Cases by Industry Six common workflows where speech-to-speech replaces a re-recording session, a second studio booking, or a multilingual voice cast. Localisation studios One English ad read needs Spanish, French, German, and Japanese versions for a campaign launch on Friday. Run speech-to-speech on the source recording against native voices in each language. Ship four localised audio tracks the same day, with the original delivery intact. Podcasters A flubbed line in an episode that already aired everywhere except the sponsor read at minute 14. Re-record the corrected line, retarget it through your cloned host voice using speech-to-speech, drop the new clip into the timeline. The fix is invisible. E-learning teams Course modules recorded by an in-house SME who is no longer available, but updates are needed for a compliance refresh. Record the new sections in any voice. Retarget through the SME's previously cloned voice (with their consent). The refreshed course keeps the original speaker identity. Game and animation studios A small cast of voice actors needs to cover 40 distinct character voices for a launch trailer. Direct one actor to deliver every line with the right emotional shape. Retarget each line through a different target voice in the library. Forty characters from one performance session. Accessibility teams A founder living with vocal fold paralysis wants to record weekly company-wide video updates. The founder records at their natural pace. Speech-to-speech retargets the audio through a clearer voice while preserving every word, every pause, every emotional inflection. Audiobook publishers ADR for a chapter where the original narrator is unavailable, but listener expectations require voice continuity. Record the corrected passage with any reader. Retarget through the narrator's cloned voice with speech-to-speech. The chapter ships without a re-booking. Speech-to-Speech supported languages 🇬🇧 English 🇪🇸 Spanish 🇫🇷 French 🇩🇪 German 🇮🇹 Italian 🇵🇹 Portuguese 🇯🇵 Japanese 🇨🇳 Chinese 🇰🇷 Korean 🇮🇳 Hindi 🇸🇦 Arabic 🇷🇺 Russian 🇳🇱 Dutch 🇵🇱 Polish 🇹🇷 Turkish 🇸🇪 Swedish 🇹🇭 Thai 🇻🇳 Vietnamese 🇮🇩 Indonesian 🇮🇱 Hebrew 🇬🇧 English 🇪🇸 Spanish 🇫🇷 French 🇩🇪 German 🇮🇹 Italian 🇵🇹 Portuguese 🇯🇵 Japanese 🇨🇳 Chinese 🇰🇷 Korean 🇮🇳 Hindi 🇸🇦 Arabic 🇷🇺 Russian 🇳🇱 Dutch 🇵🇱 Polish 🇹🇷 Turkish 🇸🇪 Swedish 🇹🇭 Thai 🇻🇳 Vietnamese 🇮🇩 Indonesian 🇮🇱 Hebrew Trust and ethics Voice cloning consent, watermarking , and commercial license The four principles that govern how Synthesys speech-to-speech handles voices, recordings, and rights. Consent first You must hold explicit consent for any voice you upload, retarget, or clone. That covers your own voice, talent licensed with signed release forms, voice artists with written permission, or voices in the public domain. Synthesys terms of service prohibit non-consensual voice cloning, impersonation, and fraud. Accounts found in violation are terminated and content is removed. Secure handling Source recordings are encrypted in transit and processed in isolated render environments. Synthesys AI Studio never uses your source audio to train public models. Source files are removed from servers per the published privacy policy. Agencies and enterprise teams can request dedicated workspaces with additional retention controls. Commercial rights from $29 Every Synthesys plan, including Indie, ships with full commercial rights on speech-to-speech outputs. No royalties, no attribution requirements, no per-output licensing fee, no platform restrictions. Use the converted audio in paid ads, broadcast, streaming, client deliverables, and product launches. The licence is perpetual. Compliance cooperation Synthesys cooperates with platform takedown requests and with law enforcement when required. Reports of unauthorised use go to support@synthesys.io. Brand-safe, rights-respecting voice work is the only kind worth scaling — and the product surface enforces that, not just the policy page. Read the full ethics policy , terms of service , and privacy policy . Report concerns to support@synthesys.io . What Teams Are Saying " Their AI models are incredibly advanced — so realistic it's almost impossible to tell they're AI-generated. The quality has consistently improved. " YL Dr Yara Loua Healthcare Professional · Verified Trustpilot Review