Google STT v2语音适配提示对同音词无效问题求助

使用Google Speech-to-Text（STT）v2版本时，遇到语音适配提示（对应v1的上下文功能）失效问题：添加提示短语"u"后，目标音频仍被识别为"you"，但相同音频在v1版本中可正确识别为"u"。

目标音频为Base64格式，可解码播放。

v2请求与响应 #

请求负载 #

POST https://{url}/v2/projects/{project_name}/locations/{stt_location}/recognizers/_:recognize

{
    "config": {
        "model": "short",
        "languageCodes": [
            "en-US"
        ],
        "autoDecodingConfig": {},
        "adaptation": {
            "phraseSets": [
                {
                    "inlinePhraseSet": {
                        "phrases": [
                            {
                                "value": "u",
                                "boost": 10
                            }
                        ],
                        "boost": 10
                    }
                }
            ]
        }
    },
    "content": <base64_audio>
}

响应结果 #

{
    "metadata": {
        "totalBilledDuration": "2s"
    },
    "results": [
        {
            "alternatives": [
                {
                    "transcript": "you",
                    "confidence": 0.71810806
                }
            ],
            "resultEndOffset": "1.590s",
            "languageCode": "en-us"
        }
    ]
}

排查尝试 #

尝试将boost值调整为0-20区间内的数值，识别结果无变化；使用文档说明会触发错误的-1值，也未收到报错，无法确认提示短语是否被系统处理。

v1参考请求与响应 #

请求负载 #

POST https://speech.googleapis.com/v1/speech:recognize

{
    "config": {
        "encoding": "WEBM_OPUS",
        "languageCode": "en",
        "sampleRateHertz": 48000,
        "speechContexts": {
            "phrases": [
                "u"
            ]
        }
    },
    "audio": {
        "content": <base64_audio>
    }
}

响应结果 #

{
    "results": [
        {
            "alternatives": [
                {
                    "transcript": "U",
                    "confidence": 0.8393447
                }
            ],
            "resultEndTime": "1.230s",
            "languageCode": "en-us"
        }
    ],
    "totalBilledTime": "2s",
    "requestId": "1673882512317147501",
    "usingLegacyModels": true
}

问题诉求 #

1. 如何确认提示短语是否被系统处理生效？
2. 如何实现与v1版本一致的识别效果？

内容的提问来源于stack exchange，提问作者tri samsul