public com.google.protobuf.DurationOrBuilder getStartTimeOrBuilder() {
      if (startTimeBuilder_ != null) {
        return startTimeBuilder_.getMessageOrBuilder();
      } else {
        return startTime_ == null ? com.google.protobuf.Duration.getDefaultInstance() : startTime_;
      }
    }
<pre>
Time offset relative to the beginning of the audio,
and corresponding to the start of the spoken word.
This field is only set if `enable_word_time_offsets=true` and only
in the top hypothesis.
This is an experimental feature and the accuracy of the time offset can
vary.
</pre>

<code>.google.protobuf.Duration start_time = 1;</code>
java-speech/proto-google-cloud-speech-v1/src/main/java/com/google/cloud/speech/v1/WordInfo.java