Use device profiles for generated audio

This page describes how to select a device profile for audio created by Text-to-Speech.

You can optimize the synthetic speech produced by Text-to-Speech for playback on different types of hardware. For example, if your app runs primarily on smaller, 'wearable' types of devices, you can create synthetic speech from Text-to-Speech API that is optimized specifically for smaller speakers.

You can also apply multiple device profiles to the same synthetic speech. The Text-to-Speech API applies device profiles to the audio in the order provided in the request to the text:synthesize endpoint. Avoid specifying the same profile more than once, as you can have undesirable results by applying the same profile multiple times.

Use of audio profiles is optional. If you choose to use one (or more), Text-to-Speech applies the profile(s) to your post-synthesized speech results. If you choose not to use an audio profile, you will receive your speech results without any post-synthesis modifications.

To hear the difference between audio generated from different profiles, compare the two clips below.

Example 1. Audio generated with handset-class-device profile

Example 2. Audio generated with telephony-class-application profile

Note: Each audio profile has been optimized for a specific device by adjusting a range of audio effects. However, the make and model of the device used to tune the profile may not match users' playback devices exactly. You may need to experiment with different profiles to find the best sound output for your application.

Available audio profiles

The following table gives the IDs and examples of the device profiles available for use by the Text-to-Speech API.

Audio profile ID	Optimized for
wearable-class-device	Smart watches and other wearables, like Apple Watch, Wear OS watch
handset-class-device	Smartphones, like Google Pixel, Samsung Galaxy, Apple iPhone
headphone-class-device	Earbuds or headphones for audio playback, like Sennheiser headphones
small-bluetooth-speaker-class-device	Small home speakers, like Google Home Mini
medium-bluetooth-speaker-class-device	Smart home speakers, like Google Home
large-home-entertainment-class-device	Home entertainment systems or smart TVs, like Google Home Max, LG TV
large-automotive-class-device	Car speakers
telephony-class-application	Interactive Voice Response (IVR) systems

Specify an audio profile to use

To specify an audio profile to use, set the effectsProfileId field for the speech synthesis request.

Protocol

To generate an audio file, make a POST request and provide the appropriate request body. The following shows an example of a POST request using curl. The example uses the Google Cloud CLI to retrieve an access token for the request. For instructions on installing the gcloud CLI, see Authenticate to Text-to-Speech.

The following example shows how to send a request to the text:synthesize endpoint.

curl \
  -H "Authorization: Bearer "$(gcloud auth print-access-token) \
  -H "Content-Type: application/json; charset=utf-8" \
  --data "{
    'input':{
      'text':'This is a sentence that helps test how audio profiles can change the way Cloud Text-to-Speech sounds.'
    },
    'voice':{
      'languageCode':'en-us',
    },
    'audioConfig':{
      'audioEncoding':'LINEAR16',
      'effectsProfileId': ['telephony-class-application']
    }
  }" "https://texttospeech.googleapis.com/v1beta1/text:synthesize" > audio-profile.txt

If the request is successful, the Text-to-Speech API returns the synthesized audio as base64-encoded data contained in the JSON output. The JSON output in the audio-profiles.txt file looks like the following:

{
  "audioContent": "//NExAASCCIIAAhEAGAAEMW4kAYPnwwIKw/BBTpwTvB+IAxIfghUfW.."
}

To decode the results from the Cloud Text-to-Speech API as an MP3 audio file, run the following command from the same directory as the audio-profiles.txt file.

sed 's|audioContent| |' < audio-profile.txt > tmp-output.txt && \
tr -d '\n ":{}' < tmp-output.txt > tmp-output-2.txt && \
base64 tmp-output-2.txt --decode > audio-profile.wav && \
rm tmp-output*.txt

Go

To learn how to install and use the client library for Text-to-Speech, see Text-to-Speech client libraries. For more information, see the Text-to-Speech Go API reference documentation.

To authenticate to Text-to-Speech, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import (
	"fmt"
	"io"
	"io/ioutil"

	"context"

	texttospeech "cloud.google.com/go/texttospeech/apiv1"
	"cloud.google.com/go/texttospeech/apiv1/texttospeechpb"
)

// audioProfile generates audio from text using a custom synthesizer like a telephone call.
func audioProfile(w io.Writer, text string, outputFile string) error {
	// text := "hello"
	// outputFile := "out.mp3"

	ctx := context.Background()

	client, err := texttospeech.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("NewClient: %w", err)
	}
	defer client.Close()

	req := &texttospeechpb.SynthesizeSpeechRequest{
		Input: &texttospeechpb.SynthesisInput{
			InputSource: &texttospeechpb.SynthesisInput_Text{Text: text},
		},
		Voice: &texttospeechpb.VoiceSelectionParams{LanguageCode: "en-US"},
		AudioConfig: &texttospeechpb.AudioConfig{
			AudioEncoding:    texttospeechpb.AudioEncoding_MP3,
			EffectsProfileId: []string{"telephony-class-application"},
		},
	}

	resp, err := client.SynthesizeSpeech(ctx, req)
	if err != nil {
		return fmt.Errorf("SynthesizeSpeech: %w", err)
	}

	if err = ioutil.WriteFile(outputFile, resp.AudioContent, 0644); err != nil {
		return err
	}

	fmt.Fprintf(w, "Audio content written to file: %v\n", outputFile)

	return nil
}

Java

To learn how to install and use the client library for Text-to-Speech, see Text-to-Speech client libraries. For more information, see the Text-to-Speech Java API reference documentation.

To authenticate to Text-to-Speech, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

/**
 * Demonstrates using the Text to Speech client with audio profiles to synthesize text or ssml
 *
 * @param text the raw text to be synthesized. (e.g., "Hello there!")
 * @param effectsProfile audio profile to be used for synthesis. (e.g.,
 *     "telephony-class-application")
 * @throws Exception on TextToSpeechClient Errors.
 */
public static void synthesizeTextWithAudioProfile(String text, String effectsProfile)
    throws Exception {
  // Instantiates a client
  try (TextToSpeechClient textToSpeechClient = TextToSpeechClient.create()) {
    // Set the text input to be synthesized
    SynthesisInput input = SynthesisInput.newBuilder().setText(text).build();

    // Build the voice request
    VoiceSelectionParams voice =
        VoiceSelectionParams.newBuilder()
            .setLanguageCode("en-US") // languageCode = "en_us"
            .setSsmlGender(SsmlVoiceGender.FEMALE) // ssmlVoiceGender = SsmlVoiceGender.FEMALE
            .build();

    // Select the type of audio file you want returned and the audio profile
    AudioConfig audioConfig =
        AudioConfig.newBuilder()
            .setAudioEncoding(AudioEncoding.MP3) // MP3 audio.
            .addEffectsProfileId(effectsProfile) // audio profile
            .build();

    // Perform the text-to-speech request
    SynthesizeSpeechResponse response =
        textToSpeechClient.synthesizeSpeech(input, voice, audioConfig);

    // Get the audio contents from the response
    ByteString audioContents = response.getAudioContent();

    // Write the response to the output file.
    try (OutputStream out = new FileOutputStream("output.mp3")) {
      out.write(audioContents.toByteArray());
      System.out.println("Audio content written to file \"output.mp3\"");
    }
  }
}

Node.js

To learn how to install and use the client library for Text-to-Speech, see Text-to-Speech client libraries. For more information, see the Text-to-Speech Node.js API reference documentation.

To authenticate to Text-to-Speech, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

/**
 * TODO(developer): Uncomment these variables before running the sample.
 */
// const text = 'Text you want to vocalize';
// const outputFile = 'YOUR_OUTPUT_FILE_LOCAtION;
// const languageCode = 'LANGUAGE_CODE_FOR_OUTPUT';
// const ssmlGender = 'SSML_GENDER_OF_SPEAKER';

// Imports the Google Cloud client library
const speech = require('@google-cloud/text-to-speech');
const fs = require('fs');
const util = require('util');

// Creates a client
const client = new speech.TextToSpeechClient();

async function synthesizeWithEffectsProfile() {
  // Add one or more effects profiles to array.
  // Refer to documentation for more details:
  // https://cloud.google.com/text-to-speech/docs/audio-profiles
  const effectsProfileId = ['telephony-class-application'];

  const request = {
    input: {text: text},
    voice: {languageCode: languageCode, ssmlGender: ssmlGender},
    audioConfig: {audioEncoding: 'MP3', effectsProfileId: effectsProfileId},
  };

  const [response] = await client.synthesizeSpeech(request);
  const writeFile = util.promisify(fs.writeFile);
  await writeFile(outputFile, response.audioContent, 'binary');
  console.log(`Audio content written to file: ${outputFile}`);
}

Python

To learn how to install and use the client library for Text-to-Speech, see Text-to-Speech client libraries. For more information, see the Text-to-Speech Python API reference documentation.

To authenticate to Text-to-Speech, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

def synthesize_text_with_audio_profile():
    """Synthesizes speech from the input string of text."""
    from google.cloud import texttospeech

    text = "hello"
    output = "output.mp3"
    effects_profile_id = "telephony-class-application"
    client = texttospeech.TextToSpeechClient()

    input_text = texttospeech.SynthesisInput(text=text)

    # Note: the voice can also be specified by name.
    # Names of voices can be retrieved with client.list_voices().
    voice = texttospeech.VoiceSelectionParams(language_code="en-US")

    # Note: you can pass in multiple effects_profile_id. They will be applied
    # in the same order they are provided.
    audio_config = texttospeech.AudioConfig(
        audio_encoding=texttospeech.AudioEncoding.MP3,
        effects_profile_id=[effects_profile_id],
    )

    response = client.synthesize_speech(
        input=input_text, voice=voice, audio_config=audio_config
    )

    # The response's audio_content is binary.
    with open(output, "wb") as out:
        out.write(response.audio_content)
        print('Audio content written to file "%s"' % output)

Additional languages

C#: Please follow the C# setup instructions on the client libraries page and then visit the Text-to-Speech reference documentation for .NET.

PHP: Please follow the PHP setup instructions on the client libraries page and then visit the Text-to-Speech reference documentation for PHP.

Ruby: Please follow the Ruby setup instructions on the client libraries page and then visit the Text-to-Speech reference documentation for Ruby.