I do have a thin foam cover over mine but I also do something else. The screen being parallel to your listening position is a big part of the problem. Mine is on a swivel and I position it on about a 30' angle so it's reflection is scattered in another direction. This reduces the vocal glare tremendously.
I don't use the TV often so I'll sometimes forget to reorient it. But it's immediately apparent when I listen to music and when I swivel the screen it goes away.