public com.google.cloud.texttospeech.v1beta1.AdvancedVoiceOptionsOrBuilder
        getAdvancedVoiceOptionsOrBuilder() {
      if (advancedVoiceOptionsBuilder_ != null) {
        return advancedVoiceOptionsBuilder_.getMessageOrBuilder();
      } else {
        return advancedVoiceOptions_ == null
            ? com.google.cloud.texttospeech.v1beta1.AdvancedVoiceOptions.getDefaultInstance()
            : advancedVoiceOptions_;
      }
    }
<pre>
Advanced voice options.
</pre>

<code>
optional .google.cloud.texttospeech.v1beta1.AdvancedVoiceOptions advanced_voice_options = 8;
</code>
java-texttospeech/proto-google-cloud-texttospeech-v1beta1/src/main/java/com/google/cloud/texttospeech/v1beta1/SynthesizeSpeechRequest.java