Automatic captions are only as good as the audio they hear. The good news is that most improvements are small, practical changes your AV or IT staff can make without new equipment.
Why audio matters more than video
SentraCaptions listens to the audio in the stream your encoder sends. Video quality doesn't affect captions at all. What matters is whether each speaker's words come through clearly, at a steady level, without much background noise.
Translations are built from the captions, so better audio also means better translations in every language you've chosen. Every screen labels captions as automatic and notes they may contain errors, but clear audio gives them the best chance.
Microphone habits at the dais
Most caption problems in a chamber come down to how people use the microphones. A short reminder to members and staff at the start of the year goes a long way.
- Speak into the microphone. Keep a consistent distance, and point the microphone toward the mouth rather than the chest.
- Turn the microphone on before speaking. The first words after someone forgets are often lost, both for captions and for viewers at home.
- Avoid speaking over each other. Overlapping speech is hard for anyone to follow, and captions are no exception. The chair can help by recognizing speakers one at a time.
- Keep side conversations off-mic. Muting when not speaking keeps stray remarks and paper shuffling out of the captions.
The public comment podium
Public comment is where audio quality varies the most, because every speaker is different.
- Set the podium microphone at a height that works for most people, and make it easy to adjust.
- Ask staff or the chair to remind speakers to step up to the microphone.
- If residents speak in another language, captions follow the audio they hear. See Captioning public comment in more than one language.
For remote public comment by phone or video, the caller's audio quality also matters. Check that remote audio is mixed into the stream at a level close to the room microphones. See Remote public comment under SB 707, and captions for remote participants.
Levels and mixing
Your audio mixer or DSP determines what goes into the stream. A few settings make a noticeable difference.
- Keep levels steady. Very quiet audio and audio that clips (distorts when too loud) are both harder to caption. Aim for a consistent level across speakers.
- Use automatic mixing if you have it. Many chamber systems can lower unused microphones automatically. That reduces room noise and echo picked up by open mics.
- Watch out for echo. If the room's speakers feed back into the microphones, or remote audio is echoing, captions can pick up words twice.
- Keep music and background audio out of the main feed. Hold music or video played in the chamber can confuse captions. Consider pausing captions during long non-speech segments.
Presentations and videos played in the meeting
When staff play a video during a meeting, captions will try to follow its audio. If the audio is clear and routed into the mixer, that usually works. If it is played through a laptop's speakers and picked up by a dais microphone, it will be harder to caption. Routing presentation audio directly into the mixer is the better approach.
Test with a real run-through
The best way to find audio problems is to try it. Before your first captioned meeting:
- Run a test meeting with a few people speaking at the dais, the podium and on a remote line.
- Watch the chamber screen and a phone page as they talk.
- Note which microphones or positions give weaker results and adjust.
- Check how local names come out, and add any that are misspelled to the glossary. See Getting local names right: building a caption glossary.
Review a transcript afterward, too. Transcripts are available in every language as TXT or SRT files, and reading one is a quick way to spot recurring trouble spots.
Recess, closed session and breaks
When the room goes quiet or the body leaves for closed session, open microphones can pick up hallway noise and conversations. Pause captions during these times. While paused, nothing is captioned, translated, stored or billed, and the screens show "Paused".
If your agency uses CivicCA, captioning pauses for recess and closed session as part of running the meeting, so staff have one less thing to remember.