@java.lang.Override
  protected Builder newBuilderForType(com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
    Builder builder = new Builder(parent);
    return builder;
  }
<pre>
Optional. Input only. Speaking rate/speed, in the range [0.25, 2.0]. 1.0 is
the normal native speed supported by the specific voice. 2.0 is twice as
fast, and 0.5 is half as fast. If unset(0.0), defaults to the native 1.0
speed. Any other values &lt; 0.25 or &gt; 2.0 will return an error.
</pre>

<code>
double speaking_rate = 3 [(.google.api.field_behavior) = INPUT_ONLY, (.google.api.field_behavior) = OPTIONAL];
</code>

@return The speakingRate.
java-texttospeech/proto-google-cloud-texttospeech-v1/src/main/java/com/google/cloud/texttospeech/v1/StreamingAudioConfig.java