public com.google.cloud.texttospeech.v1.VoiceSelectionParams.Builder getVoiceBuilder() {
      bitField0_ |= 0x00000002;
      onChanged();
      return getVoiceFieldBuilder().getBuilder();
    }
<pre>
Required. The desired voice of the synthesized audio.
</pre>

<code>
.google.cloud.texttospeech.v1.VoiceSelectionParams voice = 2 [(.google.api.field_behavior) = REQUIRED];
</code>
java-texttospeech/proto-google-cloud-texttospeech-v1/src/main/java/com/google/cloud/texttospeech/v1/SynthesizeSpeechRequest.java