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Speech to Text: start task

POST 
/api/technology/speech-to-text

Start a Speech to Text task for a media file.

Speech to Text features​

  • Multi-channel audio files are supported.
  • Channel id is included in individual transcription segments.
  • The built-in vocabulary can be extended using config field of multipart/form-data. The value of config is a string in JSON format.

Fine-tuning the transcription​

It is possible to gain finer control over the Speech to Text transcription in two ways. Firstly, you may specify an array of preferred phrases, which will be prioritized in ambiguous cases. Secondly, you can extend the built-in vocabulary by providing an array of additional words. These two options can be used either in tandem or independently.

Preferred phrases​

In case of unclear speech, the Speech to Text technology usually prefers word that makes more sense in the given context. For example, it might be impossible to determine whether a speaker said "I'm going to cell my car" or "I'm going to sell my car". However, the context suggests that the speaker is probably talking about selling their car. In other cases though, it might not be as clear. Consider the following sentence: "He bought flour in the shop". In the given context, the flour might very well be flower.

Preferred phrases allow you to leverage your unique knowledge of recording's context and prompt the technology with utterances that are expected to appear in the speech. This is especially helpful for transcribing predictable or domain-specific conversations.

Additional words​

You may use this configuration option to specify pronunciation of words that occur in preferred phrases. If the words from preferred phrases don't have explicitly specified pronunciation, one of two things can happen. Either a word is known by the technology's vocabulary and a built-in (and thus precise) pronunciation is used. Or it is an unknown word and the technology does its best to generate a default pronunciation based on the word's written form. Take note that this may result in incorrect pronunciations, especially with words foreign to the recording's language. Therefore, relying on auto-generated pronunciation is discouraged.

Alternatively, this option can be used to extend the technology's built-in vocabulary by new words. This is especially useful for industry-specific terms, foreign words, slang or neologisms. Another use case is adding region- or country-specific pronunciations to otherwise known words. Again, it is not mandatory to provide a pronunciation for new words, but the same limitations as described above apply.

Request​

Query Parameters

    language Languagerequired

    A string specifying the language for Speech to Text Phonexia. The value should follow RFC 5646. It can consist of the "language", "region", and "privateuse" subtags. Refer to supported languages for a complete list of supported language tags.

    channel_mode Channel Mode

    Possible values: [split, mix]

    A string enumeration value representing the channel mode for conversion. This value indicates how the audio channels should be processed during conversion. Only the channels with the specified indices (channels parameter) will be processed, and others will be ignored.

    Default value: split
    channels Channels

    A string of integers separated by comma (without spaces), representing the channels that should be kept during conversion. If specified, only the channels with the specified indices will be processed, and others will be ignored. If empty, all channels in the audio data will be processed. Note that channels is 0-based.

    Default value:

Header Parameters

    x-correlation-id X-Correlation-Id

    Correlation ID is a special type of request ID which is unique over a series of requests and responses, identifying a transaction in a distributed system. Correlation ID will be generated if not provided.

    Default value:
    x-request-id X-Request-Id

    In distributed system architecture (microservices architecture) it is a unique ID of request and response combination throughout all components of a distributed system. Request ID will be generated if not provided.

    Default value:

Bodyrequired

    filebinaryrequired

    Input media file.

    config object

    Optional configuration for Speech to Text.

    preferred_phrasesstring[]

    Array of phrases (made of one or many words) that are expected to appear in the media file. Phrases provided here are preferred over other variants in the transcription.

    Possible values: non-empty

    Default value: []
    additional_words object[]

    Array of words, optionally with explicitly defined pronunciations. Words provided here extend the underlying language model for the given request. This is useful for adding names, slang, foreign or jargon terms or local pronunciations of common words. These are typically not included in the model's built-in vocabulary. This can also be used for specifying pronunciations of words that occur in preferred phrases.

  • Array [
    • spellingSpelling (string)required

    The grapheme representation of the word. If you only use graphemes of the given language, you don't have to specify a pronunciation. If the word is known by the technology, a built-in pronunciation will be used. A new one will be generated otherwise. However, note that generated pronunciations may be incorrect for abbreviations, foreign words and other words with unusual spelling. You can also use graphemes outside of the language's valid grapheme set. In that case, you have to specify at least one pronunciation, otherwise the word will be rejected. Take note that only single words (without spaces) are accepted.

    Possible values: non-empty

    pronunciationsstring[]

    Array of the word's pronunciations. Each pronunciation must be specified using only supported phonemes of the given language. Unless the pronunciation is already known by the language model, it must contain at least three phonemes. Individual phonemes must be separated by a space. Take special care when using phonemes that contain the backslash character (\), as it has special meaning in JSON. You need to escape the backslash with another backslash to supress its special meaning.

    Possible values: non-empty

    Default value: []
  • ]

Responses​

Speech to Text task was accepted. Follow the X-Location header to poll for the task state.

Response Headers
    X-Location

    A URL the client should poll for task state and result.

    Example: /api/technology/speech-to-text/123e4567-e89b-12d3-a456-426614174000
Schema
    task objectrequired
    task_iduuidrequired
    stateTaskInfoState (string)required

    Possible values: [pending, running, rejected, failed, done]

var client = new HttpClient();
var request = new HttpRequestMessage(HttpMethod.Post, "https://docs.cloud.phonexia.com/api/technology/speech-to-text");
request.Headers.Add("Accept", "application/json");
var content = new StringContent(string.Empty);
content.Headers.ContentType = new MediaTypeHeaderValue("multipart/form-data");
request.Content = content;
var response = await client.SendAsync(request);
response.EnsureSuccessStatusCode();
Console.WriteLine(await response.Content.ReadAsStringAsync());