The box is not checked in Sounds. Yes, I am getting the updates - received one today. Just not the voice. I check the about avast to see that I have the recent update.
Is your sound card/chip working outside of this ?
Are the avast! antivirus sounds listed in the Sounds and Audio Devices Properties window (see image), click the Settings... button in the Program Settings, Sound section ?
Try a repair of avast. Add Remove programs, select 'avast! Anti-Virus,' click the Change/Remove button and scroll down to Repair, click next and follow. This has in the past resolved this out of sync issue between reported and actual VPS version.