public Builder clearSampleRateHertz() {
      bitField0_ = (bitField0_ & ~0x00000002);
      sampleRateHertz_ = 0;
      onChanged();
      return this;
    }
<pre>
Optional. The synthesis sample rate (in hertz) for this audio.
</pre>

<code>int32 sample_rate_hertz = 2 [(.google.api.field_behavior) = OPTIONAL];</code>

@return This builder for chaining.
java-texttospeech/proto-google-cloud-texttospeech-v1/src/main/java/com/google/cloud/texttospeech/v1/StreamingAudioConfig.java