public Builder setVoices(int index, com.google.cloud.texttospeech.v1beta1.Voice value) {
      if (voicesBuilder_ == null) {
        if (value == null) {
          throw new NullPointerException();
        }
        ensureVoicesIsMutable();
        voices_.set(index, value);
        onChanged();
      } else {
        voicesBuilder_.setMessage(index, value);
      }
      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