I was watching TV in bed before getting up this morning (Dec. 8, 2021) and a story came up on Channel 4 out of St. Louis about a new mask developed at SLU. A bit later I checked their web site and it was there. Here is the web site post about something I think might be good for general use as well.
https://www.kmov.com/news/slu-professor-creates-special-mask-for-singers-and-speakers/article_81434f70-57d1-11ec-a68f-830d0b186e7a.html?block_id=985911
https://www.kmov.com/news/slu-professor-creates-special-mask-for-singers-and-speakers/article_81434f70-57d1-11ec-a68f-830d0b186e7a.html?block_id=985911