Comparing COVID-19 Mentions In Captioning Versus OCR

How does the signal provided by OCR compare with that of spoken word captioning when it comes to COVID-19 mentions? The timeline below shows captioning mentions of the pandemic, representing the total number of seconds of airtime in which a COVID-19-related term was spoken.

Live Version.

The timeline below shows the same results, but for seconds of airtime in which one of the terms was displayed in the onscreen text.

Live Version.

Overall the two graphs trace a similar pattern, though onscreen text provides a much stronger signal in terms of total daily airtime. For both captioning and onscreen text BBC led early mentions, but led in captioning through June, while OCR mentions fell sharply.