VOX issues, from what I remember is normally a connection issue. Duplex sound cards are a must and if connections are crappy its the VOX that goes first.
Check your connection. Be sure its a good connection. A reboot before you game might help clean things up, was one of the things I did in the old days.
Be sure your sound and modem cards are up to date on their drivers. Also check if you have had an update you allow to happen. Some times a new update can mess with your settings. If you let them happen automatically you may not have noticed an update with a change.
Not sure why, yet. But I kinda lean Fugitives guess of maybe connection, after 1 yr was mentioned. Maybe try a few connection tweaks I posted in Hardwsre.
Try setting AH exe to High Priority in Task manager > details > right click AH. The game has to be open to do this. Even if it doesn’t fix it, it will serve you well and causes no harm.
Just feels like something might be taking priority, if its in and out.
Could be everyone got a Windows update that porked something.
<shrug> keep the details rolling, it will be figured out,