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      CLOVA Speech short text recognition API

        CLOVA Speech short text recognition API


        Article summary

        The latest service changes have not yet been reflected in this content. We will update the content as soon as possible. Please refer to the Korean version for information on the latest updates.

        Available in Classic and VPC

        version

        VersionDateChanges
        v1.0.02023.11.23.Initial draft
        v1.0.12023.12.21.Added the pronunciation check (English) feature

        Requests

        MethodRequest URI
        POSTCalls with InvokeURL of API Gateway created in the CLOVA Speech domain
        Creates a unique call URL for each domain

        API URL

        MethodRequest URI
        POSThttps://clovaspeech-gw.ncloud.com/recog/v1/stt

        Request headers

        Header NameDescription
        X-CLOVASPEECH-API-KEY{Secret Key}
        Content-Typeapplication/octet-stream

        Query Param

        namevaluerequiredvalue
        langstringtrueKor, Eng, Jpn, Chn
        assessmentboolfalseParameter that determines whether to return the pronunciation check result (Eng only)
        utterancestringfalsePronunciation check target text
        graphboolfalseParameter that determines whether to return the voice waveform
        • Assessment is enabled only when English (Eng) is selected.

        Responses

        Response bodies

        Field NameTypeDescription
        textstringResult value of the recognized sound source
        quotaintSound source length (in 15-second units)
        assessment_scoreintPronunciation score of the entire sentence (0-100)
        ref_graphint arrayArray of the voice waveform values of the standard pronunciation (positive integer, 50 samples per second)
        usr_graphint arrayArray of the voice waveform values of the entered pronunciation (positive integer, 50 samples per second)

        Example (cURL shell)

        curl --location 'https://clovaspeech-gw.ncloud.com/recog/v1/stt?lang=Eng&assessment=true&graph=true' \
        --header 'X-CLOVASPEECH-API-KEY: ${secret key}' \
        --header 'Content-Type: application/octet-stream' \
        --data '@/D:/example.mp3'
        Shell
        {
            "text": "sunday morning in an angry creditor",
            "quota": 15, "assessment_score": 14, "assessment_details": "false|{f(f):45, a(ɔː):100, l(l):97, se(s):43} ",
            "ref_graph": [
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 3, 4, 6, 8, 10, 11, 13, 15, 17, 18, 20, 21, 21, 22, 21, 21, 21, 20, 20, 19, 18, 17, 15, 14, 12, 11, 9, 7, 4, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0
            ],
            "usr_graph": [
                0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 4, 6, 7, 9, 11, 13, 15, 16, 18, 19, 20, 21, 21, 21, 21, 20, 20, 19, 18, 17, 16, 15, 13, 12, 10, 8, 6, 4, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0
            ]
        }
        JSON

        Error codes

        {
            "timestamp": 1700536699045,
            "error": {
                "errorCode": "STT005",
                "message": "Invalid Language"
            }
        }
        JSON

        API errors

        HttpStatusCodeErrorCodeErrorMessageDescription
        400400-Invalid request parameters
        401401Invalid secretInvalid secret
        413STT001Exceed Sound Data lengthVoice data length limit exceeded (60 seconds)
        400STT002Invalid Content Typecontent-type other than application/octet-stream
        400STT003Empty Sound DataNo voice data entered
        400STT005Invalid LanguageEntered data not in the selected language
        400STT004Empty LanguageNo language parameter entered
        500STT006Failed to pre-processingError during voice recognition pre-processing: check if the voice data is in the proper wav, mp3 or flac format
        500STT998Failed to STTError during voice recognition (Contact Customer Support for prompt action)
        500STT999Internal Server ErrorUnknown error (Contact Customer Support for prompt action)

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