在Google Cloud Text-to-Speech中无法通过韵律控制音量级别

Question

SSML音量属性对输出音频没有影响

以下是ssml

<speak>
    <prosody volume = "+0dB"> This is a sentence with volume 10 For GOOGLE. </prosody>
    <s><prosody volume = "+6dB"> This is a sentence with volume 6 For GOOGLE. </prosody></s> 
    <s><prosody volume = "+24dB"> This is a sentence with volume +24 For GOOGLE. </prosody></s>
    <s><prosody volume = "+48dB"> This is a sentence with volume +48 For GOOGLE.</prosody></s> <s><prosody volume = "+196dB"> This is a sentence with volume +196 For GOOGLE.</prosody></s>
</speak>

这是示例代码

  String ssml = $"<speak><prosody volume = \"+0dB\"> This is a sentence with volume 10 For GOOGLE.</prosody>" +
                $" <s><prosody volume = \"+6dB\"> This is a sentence with volume 6 For GOOGLE.</prosody></s>" +
                $" <s><prosody volume = \"+24dB\"> This is a sentence with volume +24 For GOOGLE.</prosody></s>" +
                $" <s><prosody volume = \"+48dB\"> This is a sentence with volume +48 For GOOGLE.</prosody></s>" +
                $" <s><prosody volume = \"+196dB\"> This is a sentence with volume +196 For GOOGLE.</prosody></s>" +
                $"</speak>";

Dubb（ssml）;

    public static void Dubb(string ssml)
    {
        var client = TextToSpeechClient.Create();

        // The input to be synthesized, can be provided as text or SSML.
        var input = new SynthesisInput
        {
            Ssml = ssml
        };

        // Build the voice request.
        var voiceSelection = new VoiceSelectionParams
        {
            LanguageCode = "en-US",
            SsmlGender = SsmlVoiceGender.Female
        };

        // Specify the type of audio file.
        var audioConfig = new AudioConfig
        {
            AudioEncoding = AudioEncoding.Linear16
        };


        // Perform the text-to-speech request.
        var response = client.SynthesizeSpeech(input, voiceSelection, audioConfig);

        // Write the response to the output file.
        using (var output = File.Create("output.wav"))
        {
            response.AudioContent.WriteTo(output);
        }

    }

我希望每行的音量都会增加，但不会增加。