Octave Voices

The Octave TTS API enables you to generate expressive voices through simple descriptions or specify a voice from your saved voices or from Hume’s Voice Library. This guide explains how to specify voices for synthesis, generate new ones, and save your favorites for reuse.

Specify a voice, or don’t!

Choose a voice from the voice library or let Octave dynamically generate a new one based on your text. Optionally, add a description to guide speech delivery. These descriptions help shape the voice’s characteristics, whether you’re using a saved voice or generating a new one.

Dynamic voice generation

When a voice is not specified, the generated speech is delivered in a dynamically generated voice. The text and description fields determine the characteristics of the voice.

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curl "https://api.hume.ai/v0/tts" \
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  -H "X-Hume-Api-Key: $HUME_API_KEY" \
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  --json '{
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    "utterances": [
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      {
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        "text": "Welcome to my application!"
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      }
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    ]
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  }'

Specifying a voice

When specifying a voice for the generated speech to be delivered in, you can specify a custom voice that you have designed and saved, either through the Platform UI or through the API, or a voice from Hume’s Voice Library.

The provider field in your request will default to CUSTOM_VOICE. When specifying one of your saved voices you do not need to specify a provider. However, when specifying a voice from Hume’s Voice Library you must specify HUME_AI as the provider.

In the example below, we specify a custom voice for the first utterance and a voice from Hume’s Voice Library voice in the second:

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curl "https://api.hume.ai/v0/tts" \
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  -H "X-Hume-Api-Key: $HUME_API_KEY" \
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  --json '{
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    "utterances": [
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      {
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        "text": "Welcome to my application!",
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        "voice": {
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          "id": "6e138d63-e6a9-4360-b1b9-da0bb77e3a58"
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        }
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      },
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      {
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        "text": "Thank you!",
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        "voice": {
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          "id": "5bb7de05-c8fe-426a-8fcc-ba4fc4ce9f9c",
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          "provider": "HUME_AI"
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        }
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      }
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    ]
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  }'

Saving generated voices

When you generate a voice you would like to reuse, you can save it to your voice library. This requires the generation_id from your TTS API response. Call the /v0/tts/voices endpoint with this ID and a name. Once saved, you can use the voice in future requests by specifying either its name or id.

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curl "https://api.hume.ai/v0/tts" \
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  -H "X-Hume-Api-Key: $HUME_API_KEY" \
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  --json '{
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    "utterances": [
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      {
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        "text": "Welcome to my application!"
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      }
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    ]
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  }'

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{
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  "generations": [
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    {
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      "audio": "//PExAAspDoWXjDNQgk3HJJJZNbaEPZMmTJk7QIEC...",
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      "duration": 1.589667,
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      "encoding": {
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        "format": "mp3",
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        "sample_rate": 48000
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      },
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      "file_size": 26496,
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      "generation_id": "41f7c154-fbb2-4372-8ecc-e6b7bf6ace01",
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      "snippets": [
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        [
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          {
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            "audio": "//PExAAspDoWXjDNQgk3HJJJZNbaEPZMmTJk7QIEC...",
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            "generation_id": "41f7c154-fbb2-4372-8ecc-e6b7bf6ace01",
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            "id": "37a108c4-5de7-4507-8a54-0521f5cb0383",
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            "text": "Welcome to my application!",
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            "utterance_index": 0
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          }
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        ]
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      ]
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    }
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  ],
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  "request_id": "7903e4a7-6642-491a-aa96-c6b359dd1042707439"
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}

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curl "https://api.hume.ai/v0/tts/voices" \
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  -H "X-Hume-Api-Key: $HUME_API_KEY" \
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  --json '{
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      "name": "NewVoice",
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      "generation_id": "41f7c154-fbb2-4372-8ecc-e6b7bf6ace01"
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  }'

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{
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  "name": "NewVoice",
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  "id": "41f7c154-fbb2-4372-8ecc-e6b7bf6ace01",
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  "provider": "CUSTOM_VOICE"
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}

Fetching and deleting voices

You can either fetch a list of your saved voices, or a list of Hume’s Voice Library voices, with the list voices endpoint. Should you want to delete a voice, you can do so using the delete voices endpoint.