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API Reference
Audio
Speech

Create speech

audio.speech.create(**kwargs) -> StringIO
POST/audio/speech

Generates audio from the input text.

ParametersExpand Collapse
input: String

The text to generate audio for. The maximum length is 4096 characters.

maxLength4096
model: String | SpeechModel

One of the available TTS models: tts-1, tts-1-hd, gpt-4o-mini-tts, or gpt-4o-mini-tts-2025-12-15.

Accepts one of the following:
String
SpeechModel = :"tts-1" | :"tts-1-hd" | :"gpt-4o-mini-tts" | :"gpt-4o-mini-tts-2025-12-15"
Accepts one of the following:
:"tts-1"
:"tts-1-hd"
:"gpt-4o-mini-tts"
:"gpt-4o-mini-tts-2025-12-15"
voice: String | :alloy | :ash | :ballad | 7 more

The voice to use when generating the audio. Supported built-in voices are alloy, ash, ballad, coral, echo, fable, onyx, nova, sage, shimmer, verse, marin, and cedar. Previews of the voices are available in the Text to speech guide.

Accepts one of the following:
String
:alloy | :ash | :ballad | 7 more

The voice to use when generating the audio. Supported built-in voices are alloy, ash, ballad, coral, echo, fable, onyx, nova, sage, shimmer, verse, marin, and cedar. Previews of the voices are available in the Text to speech guide.

Accepts one of the following:
:alloy
:ash
:ballad
:coral
:echo
:sage
:shimmer
:verse
:marin
:cedar
instructions: String

Control the voice of your generated audio with additional instructions. Does not work with tts-1 or tts-1-hd.

maxLength4096
response_format: :mp3 | :opus | :aac | 3 more

The format to audio in. Supported formats are mp3, opus, aac, flac, wav, and pcm.

Accepts one of the following:
:mp3
:opus
:aac
:flac
:wav
:pcm
speed: Float

The speed of the generated audio. Select a value from 0.25 to 4.0. 1.0 is the default.

minimum0.25
maximum4
stream_format: :sse | :audio

The format to stream the audio in. Supported formats are sse and audio. sse is not supported for tts-1 or tts-1-hd.

Accepts one of the following:
:sse
:audio
ReturnsExpand Collapse
StringIO

Create speech

require "openai"

openai = OpenAI::Client.new(api_key: "My API Key")

speech = openai.audio.speech.create(input: "input", model: :"tts-1", voice: :ash)

puts(speech)
Returns Examples