Time offset relative to the beginning of the audio, and
corresponding to the end 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.
A distinct integer value is assigned for every speaker within
the audio. This field specifies which one of those speakers
was detected to have spoken this word. Value ranges from '1'
to diarization_speaker_count. speaker_tag is set if
enable_speaker_diarization = 'true' and only in the top
alternative.
