Speech
Synthesize speech
Speech
Synthesize speech
Synthesizes speech from a text string and provides advanced information about the synthesis. Returns a JSON object that contains a base64-encoded audio file, the seed used in speech generation, and optionally an object detailing the duration of each spoken word.
POST
/
v1
/
ai
/
speech
Specify either speed or length, not both; otherwise a request with both will result in an 500 server error as the desired speed might not match the desired length.
The output of this POST request is a JSON object from which you must extract and decode the base64-encoded audio data. Here is an example of how to do so in your terminal:
jq -r '.audio' lmnt-output.json | base64 --decode > lmnt-audio-output.mp3
The file format of your audio output depends on the format specified in the inital request (this example assumes format=mp3).
Authorizations
Your API key; get it from your LMNT account page.
Body
multipart/form-data
The voice id of the voice to use for synthesis; voice ids can be retrieved by calls to List voices or Voice info
The text to synthesize; max 5000 characters per request (including spaces).
The desired language of the synthesized speech. Two letter ISO 639-1 code. One of de, en, es, fr, pt, zh, ko, hi. Does not work with professional clones and the blizzard model.
The model to use for synthesis. One of aurora (default) or blizzard. Learn more about models here.
The file format of the synthesized audio output, either aac, mp3, mulaw, raw, wav.
Set this to true to generate conversational-style speech rather than reading-style speech. Does not work with the blizzard model.
The desired output sample rate in Hz, one of: 8000, 16000, 24000; defaults to 24000 for all formats except mulaw which defaults to 8000.
The talking speed of the generated speech, a floating point value between 0.25 (slow) and 2.0 (fast).
Produce speech of this length in seconds; maximum 300.0 (5 minutes). Does not work with the blizzard model.
If set as true, response will contain a durations object; see definition in the response section below.
Response
200 - application/json
The base64-encoded audio file; the format is determined by the format parameter.
The seed used to generate this speech; can be used to replicate this output take (assuming the same text is resynthsized with this seed number, see here for more details).
A JSON object outlining the spoken duration of each synthesized input element (words and non-words like spaces, punctuation, etc.). See an example of this object for the input string "Hello world!"
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