Custom Voices

Verify your business, then clone a voice with the speaker's consent or design one from a description, and use it on any voice agent.

Custom Voices

A custom voice gives your voice agents a voice no other workspace has: a person on your team, cloned with their consent, or a new voice you describe in a sentence. Once it exists, it appears in the voice picker under Your voices like any other voice.

Custom voices sit behind two checks: your business is verified once, and each cloned voice carries the speaker's recorded consent. The rest of this article walks through both and then shows how to use the voice.

What you'll need

• A tenant admin login. Applying for verification and creating, renaming and deleting voices are tenant-admin actions.
• The agents:voice:manage permission to put a voice on an agent.
• Proof that your business is registered: a certificate of incorporation, business registration, or similar official document. PDF, PNG, JPEG or WebP, up to 5 files, 10 MB each.
• For a cloned voice: the speaker, a quiet room and a microphone. You can also upload recordings made elsewhere.

Custom voices are for standard voice agents. Agents on a live-audio model (Gemini Live) keep their built-in voices for now; the picker does not offer custom voices to them.

How it works

flowchart LR
  A[Apply with your<br/>registration documents] --> B{AI check}
  B -- genuine, confident --> C[Verified]
  B -- unclear --> D[Karmaflow reviews]
  D --> C
  B -- fake --> E[Not approved]
  C --> F[Clone or design<br/>a voice]
  F --> G[Pick it on a<br/>voice agent]
  G --> H[Go live: opening says<br/>AI + recorded]

Step 1: verify your business

Open Settings (the gear icon) → Channels → Custom Voices (/settings/custom-voices (sign-in required)). The page shows two steps at the top, Verify your business and Create your voices; the second opens once the first is done.

The application has four numbered sections:

1. Your business — the legal name, registration number and country, as they appear on your registration, plus your website if you have one.
2. Proof of registration — drop files on the box ("Drop files here, or click to choose"). Clear, complete pages; a photo of the original is fine if every word can be read.
3. The rules for custom voices — tick each rule. They are part of your agreement with Karmaflow.ai:
   • Only voices given with consent
   • No public figures, minors or impersonation
   • Callers are told it is an AI
   • Consent records, and withdrawal the same day
   • We follow the laws that apply to us
   • We follow Google's and Cartesia's policies
   • Karmaflow may suspend a voice
4. Sign — your name and role, and your name again as your signature.

Click Submit for verification. An AI model reads your documents straight away, usually within a minute, while the page shows Checking your documents:

What the check finds	What happens
The documents look genuine, match the name and number you entered, and the model is confident	Verified. Step 2 opens. No person needs to look.
Something is unclear: a name that does not quite match, a page that cannot be read	With Karmaflow for review. The page lists what the check noticed. A Karmaflow.ai administrator decides, and you get an email.
The documents show clear signs of being fake	Not approved. The page says why.

If Karmaflow.ai asks for more (Karmaflow needs a little more), the page says what is needed; fix it and submit again. Every outcome is emailed to the person who applied.

Karmaflow.ai can also verify a workspace without an application. The page then says Verified by Karmaflow and shows Accept the rules for custom voices: a tenant admin ticks each rule and signs once, and Create a voice opens.

Step 2: create a voice

When the workspace is verified, Your voices appears below the application, with a meter showing how many voices you have of your limit (two per workspace; Karmaflow.ai can raise it). Click Create a voice and choose Clone a voice or Design a voice.

Clone a voice

The dialog takes you through four steps.

1. Voice and speaker

   • Name for this voice — what you will see in the picker.

   • Choose the engine:

     	Cartesia	Google Gemini
     Languages	Speaks the one language it is recorded in	Speaks every language from one recording
     Speed	Starts speaking fastest on calls	—
     Consent	Checked by Karmaflow.ai (the words are transcribed and compared)	Google checks the consent recording itself
     Voice sample	10 to 60 seconds	10 to 30 seconds

   • Whose voice is it? — the speaker's full name.

   • For Cartesia, Language the voice will speak and Consent statement in (English or French). For Google Gemini, Language the speaker reads the consent statement in, one of the 30 languages Google provides a statement for; the voice itself will speak every language.

2. Consent — the speaker reads the sentence on screen aloud, word for word, in their own voice. Click Record the statement, or Upload a recording instead. Then tick the box confirming the speaker agreed to have their voice cloned and knows they can withdraw that consent at any time. The recording must be 2 to 30 seconds.
3. Voice sample — the same speaker reads the text under Read this, as if on a call. Click Record the voice sample. Speak naturally, at the distance you would on a phone. The field tells you if the take is too short, too long, too quiet or clipping; Record again replaces it.
4. Create — check the summary and click Create.

If the consent recording does not match the statement, or Google refuses the recordings, the dialog says so and takes you back to the step to fix.

What is kept: the consent recording, as evidence, for as long as the voice exists. The voice sample is sent to the voice provider and not stored by Karmaflow.ai.

Design a voice

Designing needs no recording and no speaker; it uses Google Gemini.

1. Name the voice and, under Describe it, say what it should sound like: age, warmth, pace, accent. The chips under the box are starting points. Main language is optional; the voice speaks every language either way.
2. Click Design the voice. A sample plays in the dialog.
3. Keep this voice to add it to your voices, Try again for another take (it replaces the draft), or Discard.

A draft you don't keep is deleted after an hour. Back keeps the draft: the library shows it until you keep or discard it.

Use a voice on an agent

1. Open a voice agent and click the Voice tab.
2. In the voice picker, choose the Your voices category. Your voices are listed first, each marked Yours, with a play button.
3. Click a voice to select it, and save the agent.

You can also choose a custom voice per language under the agent's language voices; it is listed as Your voice: followed by its name. A custom voice on a language row counts like the agent's own voice: the check below applies, and calls that switch into it carry the custom-voice charge.

Under the picker, whenever the agent speaks a custom voice, the form checks the agent's opening. An agent on a custom voice goes live only when its opening tells callers they are speaking with an AI and that the call may be recorded, either in the static greeting or in the instructions for the first turn. If the opening is missing either part, the form says which, and pushing the agent live is refused with the same reason. See Testing, Drafts and Going Live.

Manage your voices

Each voice card on Settings → Channels → Custom Voices shows:

• whether it was cloned or designed, the engine and the language;
• for a cloned voice, Consent of the speaker on file, how it was checked and when;
• the agents that use it, each linked;
• for a Google voice, how long Google keeps it: a year after it last spoke, renewed every time it speaks.

Rename a voice with the pencil icon. If Karmaflow.ai switches custom voices off for your workspace, the voices stay listed here, marked Switched off, so you can still see which agents use them and delete them. Delete is disabled while any agent, live or draft, uses the voice: choose another voice on those agents first. Deleting removes the voice at the provider and deletes the consent recording; the record of who consented, and when, stays.

Billing

Calls spoken in a custom voice add $0.06 per minute on top of the call's own minutes. The line appears on your usage as Custom voice minutes. A call is charged the extra only once a custom voice has actually spoken on it — the agent's own voice or a language voice it switched to. A call that could not use the custom voice (see below) and never spoke it is not charged the extra.

When a call cannot use the voice

If a voice was deleted, expired at Google, or custom voices were switched off for your workspace — or your workspace has reached a cap Karmaflow.ai set on custom-voice minutes — the agent does not go silent: it speaks a standard voice instead — a Google voice in place of a Google custom voice, so it keeps speaking every language, or the default Cartesia voice in place of a Cartesia clone. The same happens for a custom voice on a language row. You can see it in three places:

• the call detail page shows a Custom voice card saying the call spoke a standard voice and why — or, when the provider refused the voice mid-call, the minute it switched;
• the voice picker on the agent names the voice and says it is not available;
• the voice's card in your library is marked (Switched off, Expired at Google, Not available). A Google voice that Google no longer has is marked Expired at Google the first time a call finds out, so later calls go straight to the standard voice.

If you switch custom voices back on — Karmaflow.ai approves your workspace again, including after you apply again — the voices that were switched off come back as they were.

Troubleshooting

The application stays on "Checking your documents". The check normally finishes within a minute. If it does not, Karmaflow.ai reviews the application by hand and you receive an email with the outcome.

"The rules have changed". Karmaflow.ai updated the rules. Voices you already have keep working; tick and sign the new version to create another.

The consent recording was refused. Read the statement word for word, in the language selected, in one take, with no one else speaking. For Google voices, the consent and the sample must be the same speaker.

"Create a voice" is disabled. You are at your limit. Delete a voice you no longer use, or ask Karmaflow.ai for more.

Related

• Voices, Greetings and Pronunciation
• Multilingual Calls and Language Detection
• Calls, Transcripts and Recordings
• Testing, Drafts and Going Live