Telnyx Voice: Voice Design — Full Documentation

Complete page content for Voice Design (Voice section) of the Telnyx developer docs (https://developers.telnyx.com). Root index: https://developers.telnyx.com/llms.txt · Lightweight index for this subsection: https://developers.telnyx.com/development/llms/voice-voice-design-llms-txt.md

Overview

Source: https://developers.telnyx.com/docs/voice/voice-design-lab.md

The Voice Design lets you create custom voices for text-to-speech. No recording studio, no training datasets, no waiting. Start from a description. Write what you want in plain text — age, tone, accent, energy — and the AI generates it. Start from a recording. Upload an audio clip (or record one in the browser) and the AI captures that voice identity.

Design a Voice

Overview

Source: https://developers.telnyx.com/docs/voice/voice-design-lab/design-voice/concepts.md

What voice design does

Voice design generates a synthetic voice from a natural language description. You describe what you want — age, tone, accent, pacing — and the AI creates audio samples that match. This is not voice cloning. There’s no source audio. The voice is generated from scratch based on your text prompt.

The two-step flow: design → clone

The API has two separate resources:

Voice Design — an intermediate artifact. Think of it as a draft. You can iterate on it (up to 50 versions per design). It is NOT usable for TTS directly.
Voice Clone — a production-ready voice. Created from a design. This is what you pass to AI Assistants, Call Control, and the TTS API.

POST /v2/voice_designs → generates a sample → returns design id + version
POST /v2/voice_clones  → saves the design as a usable voice → returns voice clone id

The portal hides this two-step flow behind a single “Save This Voice” button. If you’re using the API directly, you need both steps.

Quickstart

Source: https://developers.telnyx.com/docs/voice/voice-design-lab/design-voice/quickstart.md

Portal walkthrough

Select Telnyx or Minimax using the provider toggle. Write a natural language description of the voice you want — gender, age, tone, pace, texture, personality. Click Generate Samples to create three audio previews. Each reads a different script in your chosen language. Listen to each sample. Click Regenerate All to try again, or refine your description. Click Save This Voice. Give it a name and gender tag — this creates a production-ready voice clone.

Using the API

1. Create a voice design

POST /v2/voice_designs

{
  "name": "Friendly Receptionist",
  "prompt": "Female, mid-thirties. Warm and full, slightly husky.",
  "text": "Hello, thank you for calling. How can I help you today?",
  "language": "en",
  "provider": "telnyx"
}

Set "provider": "minimax" to use the Minimax provider instead.

2. Listen to the generated sample

GET /v2/voice_designs/{id}/sample

Returns audio/wav.

3. Save as a usable voice clone

A voice design is a draft. To use it in production, save it as a clone:

POST /v2/voice_clones

{
  "name": "Friendly Receptionist",
  "voice_design_id": "DESIGN_ID",
  "version": 1,
  "language": "en",
  "gender": "female"
}

Full example

Python

import telnyx

client = telnyx.Telnyx(api_key="YOUR_TELNYX_API_KEY")

# 1. Create a voice design
design = client.voice_designs.create(
    name="Friendly Receptionist",
    prompt="Female, mid-thirties. Warm and full, slightly husky.",
    text="Hello, thank you for calling. How can I help you today?",
    language="en",
    provider="telnyx",
)
design_id = design.data.id
print(f"Voice design created: {design_id}")

# 2. Download the generated audio sample
sample = client.voice_designs.download_sample(design_id)
with open("sample.wav", "wb") as f:
    f.write(sample.content)
print("Sample saved to sample.wav")

# 3. Save the design as a usable voice clone
clone = client.voice_clones.create(
    params={
        "voice_design_id": design_id,
        "name": "Friendly Receptionist",
        "language": "en",
        "gender": "female",
    }
)
print(f"Voice clone ready: {clone.data.id}")
# Use this clone ID in TTS, Call Control, or AI Assistants

Node.js

import Telnyx from 'telnyx';
import fs from 'fs';

const client = new Telnyx({ apiKey: 'YOUR_TELNYX_API_KEY' });

// 1. Create a voice design
const design = await client.voiceDesigns.create({
  name: 'Friendly Receptionist',
  prompt: 'Female, mid-thirties. Warm and full, slightly husky.',
  text: 'Hello, thank you for calling. How can I help you today?',
  language: 'en',
  provider: 'telnyx',
});
console.log(`Voice design created: ${design.data.id}`);

// 2. Download the generated audio sample
const sample = await client.voiceDesigns.downloadSample(design.data.id);
const buffer = Buffer.from(await sample.arrayBuffer());
fs.writeFileSync('sample.wav', buffer);
console.log('Sample saved to sample.wav');

// 3. Save the design as a usable voice clone
const clone = await client.voiceClones.create({
  params: {
    voice_design_id: design.data.id,
    name: 'Friendly Receptionist',
    language: 'en',
    gender: 'female',
  },
});
console.log(`Voice clone ready: ${clone.data.id}`);
// Use this clone ID in TTS, Call Control, or AI Assistants

Once saved, see Using Custom Voices for how to use it in AI Assistants, Call Control, and the TTS API.

Parameters

Source: https://developers.telnyx.com/docs/voice/voice-design-lab/design-voice/api-details.md

Providers

Set via the provider body parameter on POST /v2/voice_designs.

	Telnyx (Qwen3TTS)	Minimax
`provider` value	`"telnyx"` (default)	`"minimax"`
Generation parameters	Respected	Not supported
Languages	Auto, Chinese, English, Japanese, Korean, German, French, Russian, Portuguese, Spanish, Italian	Auto, Chinese, English, Japanese, Korean, German, French, Russian, Portuguese, Spanish, Italian
Prompt interpretation	Follows prompts closely	May interpret differently
When to use	Fine control over generation, consistent results across iterations	Try a different model’s interpretation of the same prompt

Generation Parameters

Body parameters on POST /v2/voice_designs. Telnyx provider only — ignored when provider is "minimax".

Body parameter	Default	Range	What it does
`temperature`	0.9	0–2	Higher = more varied/creative output. Lower = more predictable.
`top_k`	50	1–1000	Limits vocabulary at each generation step. Lower = more focused.
`top_p`	1.0	0–1	Nucleus sampling cutoff. Lower = fewer token choices.
`repetition_penalty`	1.05	1–2	Reduces repeated patterns in generated audio.
`max_new_tokens`	2048	100–4096	Maximum tokens to generate. Affects output length.

The defaults are a great starting point — you can skip these parameters entirely and get good results. Adjust them later if you want to fine-tune the output.

Prompting Guide

Source: https://developers.telnyx.com/docs/voice/voice-design-lab/design-voice/prompting-guide.md

Recommended format

Structure your prompt for consistent results:

<Gender>, <Age range>. <Quality/energy description>.
<1–2 sentences about timbre, pacing, delivery>

Example:

Female, mid-thirties. Warm and full, slightly husky. Moderate pace, sounds like someone who smiles while talking.

Dimensions to describe

Age

Descriptor	What it produces
”young adult”, “in their 20s”	Lighter, more energetic
”mid-thirties”, “early forties”	Balanced, mature
”elderly”, “in his 80s”	Deeper, weathered texture

Tone / Timbre

Deep / low-pitched — gravitas, authority
Smooth / rich — polished, professional
Gravelly / raspy — character, authenticity
Airy / breathy — intimate, soft
Warm / mellow — approachable, friendly

Gender

Male, female, or describe the sound directly: “a lower-pitched, husky female voice” or “a neutral, mid-pitched androgynous voice.”

Pacing

Measured / deliberate — careful, authoritative
Rapid-fire / quick — energetic, urgent
Relaxed / conversational — natural, approachable
Rhythmic — storytelling, narration

Emotion / Energy

Calm / serene — support, meditation
Enthusiastic / upbeat — marketing, announcements
Authoritative / matter-of-fact — IVR, instructions
Warm / empathetic — customer service, healthcare

Accent / Regional

Describe the regional quality you want. Be specific:

“Slight British accent” rather than “British”
“Neutral American” rather than just “American”
“Soft Southern drawl” rather than “Southern”

Use case context

Adding context helps the model understand intent:

“Customer service agent for a bank”
“Podcast narrator for true crime”
“Bedtime story reader for children”

Example prompts

Use Case	Prompt	Recommended Engine
Customer service	Female, mid-thirties. Warm and full, slightly husky. Moderate pace, sounds like someone who smiles while talking.	Minimax
IVR system	Male, late thirties. Clean and dry, matter-of-fact. Deliberate pace, pauses before numbers and details.	Telnyx
Voice agent	Female, late twenties. Clear and professional, slightly upbeat. Natural conversational pace with a helpful tone.
Podcast narrator	Male, early forties. Deep and smooth, with a rich baritone. Measured pacing, storytelling cadence.	Minimax
Empathetic support	Male, mid-thirties. Warm, slightly gravelly. Measured and unhurried. You can hear patience in the breathing rhythm.	Telnyx
Notification/alert	Female, mid-twenties. Bright and crisp. Quick pace, clear enunciation. No emotion — just information.	Minimax
Meditation guide	Female, mid-forties. Soft, airy, and serene. Extremely slow and deliberate pace. Soothing and deeply relaxing delivery.	Minimax
Energetic promo	Male, early twenties. Bright and enthusiastic, high energy. Rapid-fire pacing, sounds highly engaged and convincing.	Minimax
Audiobook (Fiction)	Male, in his 60s. Deep, weathered texture. Relaxed, storytelling cadence with a warm, nostalgic feel.	Telnyx

Common pitfalls

Too vague — “nice voice” or “good voice” produces generic output. Be specific about at least 3 dimensions.
Contradictory traits — “whisper” + “booming” confuses the model. Pick a coherent set of characteristics.
Provider differences — the same prompt may produce noticeably different results on Telnyx vs Minimax. Try both.
Ignoring the preview text — the text you provide for synthesis should match the voice’s intended use. Don’t use a cheerful script for a somber voice.

The Enhance button

The portal’s Enhance button uses AI to expand a short description into a detailed prompt.

Before (Short description)	After (Enhanced prompt)
Empathetic tech support agent	Empathetic tech support agentGender and age: Female, late 20s to early 30s.Where the voice sits: Head and chest, with a balanced resonance.Texture: Silky smooth with a faint warmth, slightly airy.Pace: Moderate, with deliberate pauses for clarity and reassurance.Distinctive quality: A gentle, patient lilt that conveys calm and understanding.
Persuasive outbound sales caller	Persuasive outbound sales callerGender and age: Female, 28-34.Where the voice sits: Throat with chest undertones.Texture: Smooth and polished, like warm honey over gravel.Pace: Brisk and rhythmic, with confident pauses for emphasis.Distinctive quality: A bright, engaging lilt that conveys enthusiasm without sounding forced.
Professional medical clinic receptionist	Professional medical clinic receptionistGender and age: Female, 28-34.Where the voice sits: Chest and throat, grounded and clear.Texture: Smooth, slightly warm, with a subtle firmness like pressed cotton.Pace: Measured and steady, with deliberate pauses for clarity.Distinctive quality: A calm, reassuring tone, as if accustomed to offering comfort in stressful moments.
Patient language tutor	Patient language tutorGender and age: Female, late 20s to early 30s.Where the voice sits: Head and chest, balanced resonance.Texture: Smooth, warm, and gently textured like soft velvet.Pace: Measured and deliberate, with thoughtful pauses and clear enunciation.Distinctive quality: A calm, encouraging lilt that feels reassuring and attentive.

This is a good starting point, but review the expanded prompt before generating — you may want to tweak specific dimensions.

Clone from Audio

Overview

Source: https://developers.telnyx.com/docs/voice/voice-design-lab/clone-voice/concepts.md

What voice cloning does

Voice cloning captures a speaker’s vocal characteristics — timbre, cadence, accent, pronunciation — from a short audio sample and applies them to new speech synthesis. The clone is a representation of the voice, not a recording of it. The system learns patterns from your audio and encodes them into parameters that guide TTS. This means:

The cloned voice can say things the original speaker never said
Clone quality is bounded by what the model can learn from your sample
Poor recordings, background noise, or inconsistent delivery degrade the clone

What cloning doesn’t do

A clone is not a recording. It’s a statistical approximation of a voice — the model extracts patterns (formant frequencies, prosodic tendencies, spectral characteristics) and applies them during synthesis. This means:

Output passes through the TTS model, which has its own characteristics. A clone sounds like the speaker, but through the lens of the model.
Quality has a ceiling set by your source audio. No amount of API parameters will fix a noisy or inconsistent recording.
The clone may not handle speech styles far from the original sample well. A voice cloned from calm narration may sound different when asked to express strong emotion.

Two ways to create a clone

Method	What it does	When to use
Upload audio	Send an audio file directly	You have a recording ready
From a voice design	Save a previously generated design as a clone	You used Design a Voice to create it

Both produce the same output: a voice clone with a voice ID you can use in production.

Recording best practices

Match your recording to your use case. Don’t read a monotone script if you want an expressive clone. The AI replicates what it hears — including energy, emotion, and pacing.
Speak clearly, avoid background noise. Use a decent microphone in a quiet space. Background noise gets cloned too. You don’t need a $10K mic — a$ 100-300 USB condenser in a quiet room is sufficient.
Avoid long pauses. The cloned voice will mimic pauses between sentences. Keep speech flowing naturally.
Trim your recording. Speech from start to finish, no dead air at the beginning or end.
Speak in the target language. If you want the clone to speak Spanish, record in Spanish.
Keep it consistent. Same tone, accent, and energy throughout. Wide fluctuations confuse the model. The AI clones everything — including stutters, “uhms”, and inconsistencies.
Aim for the right volume. Target -23 to -18 dB RMS with peaks no higher than -3 dB. Too quiet = noise floor issues. Too loud = clipping.
Audio codec doesn’t matter much. MP3 at 128 kbps or above is fine. WAV is ideal but higher bitrate MP3 won’t noticeably hurt quality.
Optimal duration by model:
- Qwen3TTS: 5–10 seconds. Auto-trims to 10s. More isn’t better.
- Ultra: Up to 10 seconds.
- Minimax: 1–2 minutes is the sweet spot. Longer recordings capture more vocal range, but beyond 3 minutes yields diminishing returns.

Quickstart

Source: https://developers.telnyx.com/docs/voice/voice-design-lab/clone-voice/quickstart.md

Upload a file

Select Telnyx or Minimax using the provider toggle. In the Voice Design, click Upload Audio and choose your file or drag and drop it. Enter a name for the voice and select the gender. Click Clone Voice. The system processes the audio and creates a voice clone, typically in a few seconds.

Record directly in the browser

Click Upload Audio, then select the Record tab. Select the language you’ll speak in. The system generates a reading script optimized for voice cloning. Click Start Recording and read the script clearly. It’s designed to capture the full range of phonemes. Listen to your recording. Re-record if needed, then click Clone Voice.

Using the API

Clone with Telnyx (default)

POST /v2/voice_clones/from_upload
Content-Type: multipart/form-data

audio_file: recording.wav
name: My Custom Voice
language: en
gender: female

Clone with Minimax

Supports longer audio (up to 5 minutes):

POST /v2/voice_clones/from_upload
Content-Type: multipart/form-data

audio_file: recording.wav
name: My Custom Voice
language: en
gender: female
provider: minimax

Clone with Ultra model

Ultra clones use the higher-quality Ultra model. The request returns 202 Accepted — poll the clone’s status until it becomes active.

POST /v2/voice_clones/from_upload
Content-Type: multipart/form-data

audio_file: recording.wav
name: My Ultra Voice
language: en
gender: female
provider: telnyx
model_id: Ultra

Response (202 Accepted):

{
  "data": {
    "id": "uuid",
    "status": "pending",
    ...
  }
}

Poll with GET /v2/voice_clones until status is active.

SDK Examples

Clone with Telnyx (default)

Python

import telnyx

client = telnyx.Telnyx(api_key="YOUR_TELNYX_API_KEY")

clone = client.voice_clones.create_from_upload(
    params={
        "audio_file": open("recording.wav", "rb"),
        "name": "My Custom Voice",
        "language": "en",
        "gender": "female",
        "provider": "telnyx",
    }
)

print("Voice Clone Created:", clone.data)

Node.js

import Telnyx from 'telnyx';
import fs from 'fs';

const client = new Telnyx({ apiKey: 'YOUR_TELNYX_API_KEY' });

const clone = await client.voiceClones.createFromUpload({
  params: {
    audio_file: fs.createReadStream('recording.wav'),
    name: 'My Custom Voice',
    language: 'en',
    gender: 'female',
    provider: 'telnyx',
  },
});

console.log('Voice Clone Created:', clone.data);

Clone with Minimax

Minimax supports longer audio (up to 20MB) and uses the speech-2.8-turbo model.

Python

import telnyx

client = telnyx.Telnyx(api_key="YOUR_TELNYX_API_KEY")

clone = client.voice_clones.create_from_upload(
    params={
        "audio_file": open("recording.wav", "rb"),
        "name": "My Custom Voice",
        "language": "en",
        "gender": "female",
        "provider": "minimax",
    }
)

print("Voice Clone Created:", clone.data)

Node.js

import Telnyx from 'telnyx';
import fs from 'fs';

const client = new Telnyx({ apiKey: 'YOUR_TELNYX_API_KEY' });

const clone = await client.voiceClones.createFromUpload({
  params: {
    audio_file: fs.createReadStream('recording.wav'),
    name: 'My Custom Voice',
    language: 'en',
    gender: 'female',
    provider: 'minimax',
  },
});

console.log('Voice Clone Created:', clone.data);

Clone with Ultra model

Ultra clones return 202 Accepted and require polling until the status is active.

Python

import telnyx
import time

client = telnyx.Telnyx(api_key="YOUR_TELNYX_API_KEY")

# Create the clone (returns 202 Accepted)
clone = client.voice_clones.create_from_upload(
    params={
        "audio_file": open("recording.wav", "rb"),
        "name": "My Ultra Voice",
        "language": "en",
        "gender": "female",
        "provider": "telnyx",
        "model_id": "Ultra",
    }
)

print("Clone submitted:", clone.data.id, "— status:", clone.data.status)

# Poll until active
while True:
    clones = client.voice_clones.list()
    for c in clones:
        if c.id == clone.data.id:
            if c.status == "active":
                print("Clone ready!")
                break
    else:
        time.sleep(5)
        continue
    break

Node.js

import Telnyx from 'telnyx';
import fs from 'fs';

const client = new Telnyx({ apiKey: 'YOUR_TELNYX_API_KEY' });

// Create the clone (returns 202 Accepted)
const clone = await client.voiceClones.createFromUpload({
  params: {
    audio_file: fs.createReadStream('recording.wav'),
    name: 'My Ultra Voice',
    language: 'en',
    gender: 'female',
    provider: 'telnyx',
    model_id: 'Ultra',
  },
});

console.log('Clone submitted:', clone.data.id, '— status:', clone.data.status);

// Poll until active
while (true) {
  const clones = await client.voiceClones.list();
  const found = clones.data.find((c) => c.id === clone.data.id);
  if (found?.status === 'active') {
    console.log('Clone ready!');
    break;
  }
  await new Promise((r) => setTimeout(r, 5000));
}

Once saved, see Using Custom Voices for how to use it in AI Assistants, Call Control, and the TTS API.

Parameters

Source: https://developers.telnyx.com/docs/voice/voice-design-lab/clone-voice/parameters.md

Models

Set via model_id (body) on POST /v2/voice_clones/from_upload, or use provider (body) to select Minimax.

Model	Provider	Audio length	Max file	Sync/Async	Best for
Qwen3TTS	Telnyx (default)	3–15s (auto-trimmed to 10s)	5 MB	Sync (201)	Short, clean samples
Ultra	Telnyx	Up to 10s	5 MB	Async (202)	Higher quality, more natural
speech-2.8-turbo	Minimax	10s–5 min	20 MB	Sync (201)	Longer recordings, more vocal range

Audio Requirements

Body parameter audio_file (multipart) on POST /v2/voice_clones/from_upload.

	Qwen3TTS	Ultra	Minimax
Audio length	3–15s (5–10s optimal)	Up to 10s	10s–5 min
Max file size	5 MB	5 MB	20 MB
Formats	WAV, MP3, FLAC, OGG, M4A	Same	Same

Qwen3TTS: aim for 5–10 seconds. Longer isn’t better — auto-trims to 10s.
Minimax: longer is better. 1–2 minutes of varied speech gives more vocal range.

The `ref_text` Parameter

Body parameter on POST /v2/voice_clones/from_upload. Optional. A transcript of what’s being said in the audio. Improves clone quality by giving the model a text reference to align against.

Ultra Async Flow

When model_id is "Ultra", the API returns 202 Accepted instead of 201:

POST /v2/voice_clones/from_upload → 202 { "data": { "status": "pending" } }

Poll until ready:

GET /v2/voice_clones/{id} → 200 { "data": { "status": "active" } }

See Responses for status values and voice ID format. See Errors for Minimax error codes.

Responses

Source: https://developers.telnyx.com/docs/voice/voice-design-lab/clone-voice/responses.md

Voice ID Format

Every clone response includes fields to construct the voice ID: {Provider}.{Model}.{provider_voice_id}

Provider	`provider_voice_id` value
Telnyx Qwen3TTS	Equals the clone’s UUID (`id` field)
Telnyx Ultra	Cartesia-assigned voice ID
Minimax	Minimax-assigned ID (encoded format)

See Using Custom Voices for how to use these IDs across products.

Clone Status

Status	Meaning
`active`	Ready to use
`pending`	Being processed (Ultra only — poll until active)
`failed`	Processing failed
`expired`	Voice was not kept alive

Qwen3TTS and Minimax clones are always active on creation.

Errors

Source: https://developers.telnyx.com/docs/voice/voice-design-lab/clone-voice/errors.md

General Errors

These errors apply to all providers.

Endpoint	Status	Code	Detail
`show`	404	`10005`	Clone not found or invalid UUID
`create`	404	`10005`	Voice design not found / no version
`create`	409	`10012`	Duplicate `provider_voice_id`
`create`	422	`10027`	Changeset validation (see below)
`create_from_upload`	422	`10027`	`audio_file is required`
`create_from_upload`	422	`10027`	`File too large. Maximum allowed size is 5MB` (20MB for Minimax)
`create_from_upload`	400	`10015`	`Failed to process audio file: <reason>` (FFmpeg failure)
`create_from_upload`	422	`10027`	Invalid `provider`+`model_id` combination
`update`	404	`10005`	Clone not found
`update`	422	`10027`	Changeset validation errors
`delete`	404	`10005`	Clone not found
`sample`	404	`10005`	Clone or sample not found

Telnyx / Cartesia Errors

Status	Code	Detail	Provider
422	`10027`	Pattern-matched messages (voice not found, audio too short/long, bad quality, unsupported format, unsupported language, invalid params, text length invalid)	Telnyx/Cartesia
429	`10011`	`Provider rate limit exceeded`	All providers

Minimax Errors

Status	Code	Detail	Provider
422	`10038`	`Audio is too short (min 10s)`	Minimax (code 2037)
422	`10038`	`Audio is too long`	Minimax (code 2038)
422	`10038`	`Audio quality too low`	Minimax (code 2039)
422	`10038`	`Audio contains too much noise`	Minimax (code 2048)
422	`10038`	`Voice cloning provider error: <msg>`	Minimax (other codes)
500	`10037`	`Voice clone service configuration error`	Auth misconfiguration detected
502	`10037`	`Voice clone service unavailable`	Upstream error or connection failure

Using Custom Voices

Source: https://developers.telnyx.com/docs/voice/voice-design-lab/using-custom-voices.md

Every voice clone gets a unique voice ID: {Provider}.{Model}.{voice_id}

Telnyx: Telnyx.Qwen3TTS.33226e69-3abd-429b-b64a-86775c9b5850
Minimax: Minimax.speech-2.8-turbo.TB4ZMVKanThGeldiw8rLBEg21v4ifjUTRgLpkodJxpMYV

Find it in the Voice Design by clicking on any saved voice, or build it from the clone response’s provider, provider_supported_models, and provider_voice_id fields.

AI Assistants

Select your custom voice in the assistant’s voice settings. Telnyx clones appear under Telnyx / Qwen3TTS, Minimax clones under Minimax.

Call Control

Pass the voice ID in the voice field of the speak command.

TTS WebSocket

Pass the voice ID as the voice query parameter on the WebSocket URL. See the TTS streaming guide for the full connection flow.

API Reference (Voice Design)

Voice Designs

List voice designs: Returns a paginated list of voice designs belonging to the authenticated account.
Create or add a version to a voice design: Creates a new voice design (version 1) when voice_design_id is omitted. When voice_design_id is provided, adds a new version to the existing design instead…
Get a voice design: Returns the latest version of a voice design, or a specific version when ?version=N is provided. The id parameter accepts either a UUID or the design name.
Rename a voice design: Updates the name of a voice design. All versions retain their other properties.
Delete a voice design: Permanently deletes a voice design and all of its versions. This action cannot be undone.
Download voice design audio sample: Downloads the WAV audio sample for the voice design. Returns the latest version’s sample by default, or a specific version when ?version=N is provided. The `…
Delete a specific version of a voice design: Permanently deletes a specific version of a voice design. The version number must be a positive integer.

Voice Clones

List voice clones: Returns a paginated list of voice clones belonging to the authenticated account.
Create a voice clone from a voice design: Creates a new voice clone by capturing the voice identity of an existing voice design. The clone can then be used for text-to-speech synthesis.
Create a voice clone from an audio file upload: Creates a new voice clone by uploading an audio file directly. Supported formats: WAV, MP3, FLAC, OGG, M4A. For best results, provide 5–10 seconds of clear spe…
Update a voice clone: Updates the name, language, or gender of a voice clone.
Delete a voice clone: Permanently deletes a voice clone. This action cannot be undone.
Download voice clone audio sample: Downloads the WAV audio sample that was used to create the voice clone.

​Telnyx Voice: Voice Design — Full Documentation

​

​Overview

​Design a Voice

​Overview

​What voice design does

​The two-step flow: design → clone

​Quickstart

​Portal walkthrough

​Using the API

​1. Create a voice design

​2. Listen to the generated sample

​3. Save as a usable voice clone

​Full example

​Parameters

​Providers

​Generation Parameters

​Prompting Guide

​Recommended format

​Dimensions to describe

​Age

​Tone / Timbre

​Gender

​Pacing

​Emotion / Energy

​Accent / Regional

​Use case context

​Example prompts

​Common pitfalls

​The Enhance button

​Clone from Audio

​Overview

​What voice cloning does

​What cloning doesn’t do

​Two ways to create a clone

​Recording best practices

​Quickstart

​Upload a file

​Record directly in the browser

​Using the API

​Clone with Telnyx (default)

​Clone with Minimax

​Clone with Ultra model

​SDK Examples

​Clone with Telnyx (default)

​Clone with Minimax

​Clone with Ultra model

​Parameters

​Models

​Audio Requirements

​The ref_text Parameter

​Ultra Async Flow

​Responses

​Voice ID Format

​Clone Status

​Errors

​General Errors

​Telnyx / Cartesia Errors

​Minimax Errors

​Using Custom Voices

​Using Custom Voices

​AI Assistants

​Call Control

​TTS WebSocket

​API Reference (Voice Design)

​Voice Designs

​Voice Clones

Telnyx Voice: Voice Design — Full Documentation

Overview

Design a Voice

Overview

What voice design does

The two-step flow: design → clone

Quickstart

Portal walkthrough

Using the API

1. Create a voice design

2. Listen to the generated sample

3. Save as a usable voice clone

Full example

Parameters

Providers

Generation Parameters

Prompting Guide

Recommended format

Dimensions to describe

Age

Tone / Timbre

Gender

Pacing

Emotion / Energy

Accent / Regional

Use case context

Example prompts

Common pitfalls

The Enhance button

Clone from Audio

Overview

What voice cloning does

What cloning doesn’t do

Two ways to create a clone

Recording best practices

Quickstart

Upload a file

Record directly in the browser

Using the API

Clone with Telnyx (default)

Clone with Minimax

Clone with Ultra model

SDK Examples

Clone with Telnyx (default)

Clone with Minimax

Clone with Ultra model

Parameters

Models

Audio Requirements

The `ref_text` Parameter

Ultra Async Flow

Responses

Voice ID Format

Clone Status

Errors

General Errors

Telnyx / Cartesia Errors

Minimax Errors

Using Custom Voices

Using Custom Voices

AI Assistants

Call Control

TTS WebSocket

API Reference (Voice Design)

Voice Designs

Voice Clones