The University of Maryland Classroom Design Manual
Design Considerations for Effective Distance Learning | University Business Magazine
Generally speaking, if the lecturer is the focus of the AV capture (and not the audience), harder surfaces where the lecturer is standing and acoustically-absorbent surfaces elsewhere are the idea. You want to allow the speaker's voice to carry and you want to deaden the rustling, coughing, shuffling, etc. in the audience. Extra lighting, and neutral colors behind the speaker help with the picture.
Naturally, it gets more complicated when you get into fully-interactive, remote learning.
