This is the reference for the v1 Lmnt Node SDK. The v2 SDK has a different API and is not compatible with this reference.

The Speech class is your primary touch-point.

Instantiate a Speech object with your 

import Speech from 'lmnt-node'

const speech = new Speech('LMNT_API_KEY')

Alternatively, you can set the LMNT_API_KEY environment variable and omit the constructor argument.

​
fetchVoices

async fetchVoices(options={})

Returns the voices available for use in speech synthesis calls.

const voices = await speech.fetchVoices()

​
Parameters

​
options
object

An optional object containing fields to update.

​
Return value

A list of voice metadata objects. Here’s a sample object:

[
  {
    "name": "Morgan",
    "id": "morgan",
    "state": "ready",
    "owner": "system",
    "starred": false,
    "gender": "F",
    "description": "UK. Young adult. Conversational"
  }
]

​
fetchVoice

async fetchVoice(voice)

Returns the voice metadata for a single voice.

const voice = await speech.fetchVoice('morgan')

​
Parameters

​
voice
string
required

The id of the voice to update. Voice ids can be retrieved from fetchVoices().

​
Return value

The voice metadata object. Here’s a sample object:

  {
    "name": "Morgan",
    "id": "morgan",
    "state": "ready",
    "owner": "system",
    "starred": false,
    "gender": "F",
    "description": "UK. Young adult. Conversational"
  }

​
createVoice

async createVoice(name, enhance, filenames, options={})

Creates a new voice from a set of audio files. Returns the voice metadata object.

const filenames = ['file1.wav', 'file2.wav']
const result = await speech.createVoice('new-voice', false, filenames)

​
Parameters

​
name
string
required

The name of the voice.

​
enhance
boolean
required

For unclean audio with background noise, applies processing to attempt to improve quality. Not on by default as it can also degrade quality in some circumstances.

​
filenames
string[]
required

A list of filenames to use for the voice.

​
options
object

​
Return value

The voice metadata object. Here’s a sample object:

{
    "id": "123444566422",
    "name": "new-voice",
    "owner": "me",
    "state": "ready",
    "starred": false,
    "description": "Totam necessitatibus saepe repudiandae perferendis. Tempora iure provident. Consequatur debitis assumenda. Earum debitis cum.",
    "type": "instant",
    "gender": "male"
}

​
updateVoice

async updateVoice(voice, options={})

Updates metadata for a specific voice. A voice that is not owned by you can only have its starred field updated. Only provided fields will be changed.

const options = {'name': 'new-voice-name', 'starred': true}
await speech.updateVoice('123444566422', options)

​
Parameters

​
voice_id
string
required

The id of the voice to update. If you don’t know the id, you can get it from list_voices().

​
options
object

The properties to update. Only provided fields will be changed.

​
Return value

The updated voice metadata object.

​
deleteVoice

async deleteVoice(voice)

Deletes a voice and cancels any pending operations on it. The voice must be owned by you. Cannot be undone.

await speech.deleteVoice('123444566422')

​
Parameters

​
voice_id
string
required

The id of the voice to delete. If you don’t know the id, you can get it from list_voices().

​
Return value

A success or error message. Here’s a sample object:

{
    "success": "true"
}

​
synthesize

async synthesize(text, voice, options={})

Synthesizes speech for a supplied text string.

const synthesis = await speech.synthesize('Hello world!', 'morgan')
const audio = synthesis.audio

​
Parameters

​
text
string
required

The text to synthesize.

​
voice
string
required

Which voice to render; id is found using the list_voices call.

​
options
object

Additional options for the synthesis request.

​
Return value

​
audio
Buffer

The synthesized audio encoded in the requested format as a Buffer object.

​
durations
array of duration objects

An array of text duration objects. Only returned if return_durations is True.

​
seed
number

The seed used for synthesis. Only returned if return_seed is True.

Here is the schema for the return value:

{
  "audio": binary-audio-file,
  "durations": [
    {
      "text": "string",
      "start": 0,
      "duration": 0
    },
    ...
  ],
  "seed": "number"
}

​
Notes

  • The mp3 bitrate is 96kbps.

​
synthesizeStreaming

synthesizeStreaming(voice, options={})

Creates a new, full-duplex streaming session. You can use the returned connection object to concurrently stream text content to the server and receive speech data from the server.

​
Parameters

​
voice
string
required

Which voice to render; id can be found using the fetchVoices call.

​
options
object

Additional options for the streaming connection.

​
Return value

A StreamingSynthesisConnection instance, which you can use to stream data.