Picture two phone bots. One sounds flat and robotic. The other sounds warm, clear, and like your brand. Which one would you rather talk to?
Building that second voice is easier than it sounds. TTS, short for text-to-speech, turns written words into spoken audio.
Moreover, many TTS platforms now let you create a voice of your own. You can describe it in a sentence, such as “a calm, friendly woman in her thirties,” or copy a real voice from a short recording, which is called cloning. That is custom voice design in a nutshell.
So which platform should you pick? Below are 5 picks that do this well, starting with Telnyx.
TL;DR
- Telnyx: Best for teams that want to design, clone, or dub a voice and use it right inside phone calls, IVRs, and AI agents.
- ElevenLabs: Best for creators and product teams that want rich voice design tools and a huge voice library.
- Resemble AI: Best for teams that need flexible hosting, including self-hosted and on-premises setups.
- Inworld AI: Best for developers who want to design or clone a voice and steer its delivery line by line.
- Cartesia: Best for real-time voice agents that need one cloned voice across many languages and accents.
Top 5 Custom Voice Platforms At A Glance
|
|
Telnyx |
ElevenLabs |
Resemble AI |
Inworld AI |
Cartesia |
|
How You Create A Voice |
Prompt design, clone, or dub |
Community library, clone, or Voice Design |
Clone or design |
Voice Design or instant clone |
Instant or Pro clone |
|
Shortest Clip Needed (Clone Path) |
About 5 to 10 seconds (default model) |
A minute or two (Instant Clone) |
About 10 seconds (Rapid) |
A few seconds (Instant Clone) |
About 10 seconds (Instant Clone) |
|
Prompt-Based Design |
Yes |
Yes |
Yes |
Yes |
No |
1. Telnyx
Telnyx is an infrastructure provider built for real-time AI agents. It runs calls and AI on its own private global network.
How Telnyx Builds Your Voice
Telnyx gives you three ways to get a custom voice. You can design one from a written prompt, clone one from a short recording, or dub audio into another language. Moreover, the voice lives on the same platform as your calls. So you can use it across Telnyx AI Assistants, Call Control (the tools that manage live phone calls), IVRs (the “press 1 for sales” menus), and the TTS WebSocket, a live connection that streams audio as it is made.
To design a voice, you simply type what it should sound like. The Enhance button adds detail to a thin prompt, and you can try up to 50 versions. To clone a voice, you upload a WAV, MP3, FLAC, OGG, or M4A file. With the default model, about 5 to 10 seconds of audio is enough.
Pros
- Three Creation Paths: Design from a prompt, clone from a clip, or dub, all in one place.
- Fast Clone Start: The default model needs only about 5 to 10 seconds of audio.
- Plenty Of Versions: Try up to 50 design versions, with an Enhance button to sharpen prompts.
- One Voice Everywhere: Use the same voice across AI Assistants, Call Control, IVRs, and the TTS WebSocket.
- Built On A Carrier: Telnyx is a licensed carrier, so voice and phone network sit together.
- Data Residency and Compliance: Options in the US, EU, Australia, and UAE, with published SOC 2, ISO, PCI, and GDPR details.
Who Telnyx Fits
Telnyx fits teams that build phone bots, contact center flows, and voice AI agents. If you want your custom voice to answer real calls without stitching several vendors together, Telnyx is a natural first stop.
2. ElevenLabs
ElevenLabs is an AI voice platform for creators, developers, and businesses. It helps them create speech, voice agents, dubs, and other audio.
How ElevenLabs Builds Your Voice
ElevenLabs Voice Design works from a text prompt between 20 and 1,000 characters, and you get three previews to choose from. You can adjust Loudness and Guidance Scale, which controls how closely the result follows your prompt. Voice Design is still experimental, so Professional clones tend to sound more consistent. For cloning, Instant Voice Cloning needs a minute or two of clean audio. Professional Voice Cloning asks for 30 minutes or more and takes several hours to train. And finally, for AI agents, ElevenLabs connects to phone systems through SIP, the standard way calls move over the internet.
Pros
- Flexible Prompts: Describe a voice in up to 1,000 characters and pick from three previews.
- Fine Controls: Loudness and Guidance Scale help you steer the result.
- Remixing: Tweak a voice you own instead of starting over.
- Huge Library: More than 10,000 community voices to try.
- Broad Language Support: 32 languages for voice creation.
- Clear Consent Steps: Consent confirmation for Instant clones and voice-captcha for Professional clones.
Who ElevenLabs Fits
ElevenLabs fits creators, media teams, and app builders who want lots of creative control. It is a strong pick when you plan to experiment with many voices before settling on one.
3. Resemble AI
Resemble AI is an enterprise AI company focused on deepfake detection, which means spotting fake AI-made media. It also offers secure tools for creating AI voices.
How Resemble Builds Your Voice
Resemble AI lets you clone a real voice or design a new one from a description. Rapid Clone needs about 10 seconds of audio and is ready in under a minute. Professional Clone uses 10 to 25 minutes or more of audio and takes about 40 minutes to train. Moreover, one clone can speak 23 languages, and you can make variants for jobs like conversational, commercial, or phone agent use. You also set custom pronunciation once, and it carries through. Hosting is where Resemble stands out. You can run it in the cloud, host it yourself, or keep it fully on-premises, even in air-gapped setups with no internet connection.
Pros
- Quick Rapid Clones: About 10 seconds of audio, ready in under a minute.
- Many Languages Per Clone: One clone speaks 23 languages.
- Hosting Choices: Cloud, self-hosted, on-premises, or air-gapped.
- Open-Source Option: Chatterbox is available under the MIT license.
- Use-Case Variants: Build different versions of one voice for different jobs.
Who Resemble Fits
Resemble fits teams with strict hosting needs, such as those in regulated industries. If you need the voice to run on your own servers, Resemble is worth a close look.
4. Inworld AI
Inworld AI is a research lab and AI provider for consumer apps. It gives developers real-time speech models and a choice of language models.
How Inworld Builds Your Voice
Inworld gives you two ways to make a custom voice. Voice Design creates a brand-new voice from a written description of things like age, gender, accent, tone, and pitch. You can write up to 1,000 characters, and Inworld returns up to three previews to compare. Instant Voice Cloning works from a short recording of just a few seconds, and the voice is ready in seconds. On its main TTS-2 model, you can steer the voice with short notes in square brackets, such as [whisper] or [shouting]. These notes change pitch, speed, volume, and style partway through a line.
Pros
- Two Creation Paths: Design a voice from a description or clone one from a short clip.
- Quick Clones: An instant clone is ready in seconds.
- Three Previews Per Design: Compare up to three options before you save a voice.
- Inline Steering: Bracket notes adjust pitch, speed, volume, and style mid-line.
- Built For Live Use: WebSocket streaming suits voice agents and interactive apps.
- Wide Language Reach: Models cover 200+ languages and locales.
Who Inworld Fits
Inworld fits developers who build voice agents, companions, and interactive apps. It suits teams that want to design or clone a voice and then direct its delivery line by line.
5. Cartesia
Cartesia is an AI lab that builds real-time voice models for businesses. It offers speech, transcription, and voice agents in one place.
How Cartesia Builds Your Voice
Cartesia builds custom voices by cloning a real recording. An instant clone starts from about 10 seconds of audio, and newer models can learn from up to 60 seconds to keep more of the speaker’s accent. Localization is a big part of the offer. You can add accents to an instant clone you own, so one voice can speak several accents natively, and Sonic covers 44 languages. Moreover, you can guide speed and volume on instant clones, emotion guidance (still in beta) works in English, and custom pronunciation dictionaries keep tricky names right. So with WebSocket streaming on top, Cartesia slots neatly into real-time voice agents.
Pros
- Short Starting Clip: About 10 seconds of audio is enough for an instant clone.
- Longer Samples Help: Newer models learn from up to 60 seconds to keep the accent.
- Pro Clones: Train on 30+ minutes of audio for a closer match.
- Accent Add-Ons: One instant clone can speak several accents natively.
- Delivery Controls: Speed, volume, and emotion guidance, plus pronunciation dictionaries.
- Flexible Deployment: Cloud, private cloud, or on-premises options for enterprise teams.
Who Cartesia Fits
Cartesia fits teams building real-time voice agents that need one cloned brand voice across several languages and accents. It suits developers who want low-latency streaming and natural delivery on live calls.
Conclusion
A custom voice is more than a nice extra. It shapes how people feel about your brand every time they hear it. Therefore, it is worth picking a platform that fits the way you actually work.
If you build phone bots, IVRs, or voice agents, Telnyx gives you prompt design, cloning, and dubbing on the same platform that runs your calls. ElevenLabs is great for creative teams that love to experiment. Resemble AI suits teams that need to host voices themselves. Inworld suits developers who want to design a voice and direct it line by line. And Cartesia works well for real-time agents that speak in many accents.
So pick the path that matches your goals, test a few voices, and let your brand start speaking for itself.