public Builder addVoices(com.google.cloud.texttospeech.v1beta1.Voice.Builder builderForValue) {
      if (voicesBuilder_ == null) {
        ensureVoicesIsMutable();
        voices_.add(builderForValue.build());
        onChanged();
      } else {
        voicesBuilder_.addMessage(builderForValue.build());
      }
      return this;
    }
<pre>
The list of voices.
</pre>

<code>repeated .google.cloud.texttospeech.v1beta1.Voice voices = 1;</code>
java-texttospeech/proto-google-cloud-texttospeech-v1beta1/src/main/java/com/google/cloud/texttospeech/v1beta1/ListVoicesResponse.java