This is just nonsense, a bug or avast bug almost unimportant.
In windows 7 64bits, before the threats a sound sounded. In fact it sounded so much in web detections, as when you did a scan and it was completed.
Well, now sounds no longer work.
I did the eicar test and it does not sound at all (and if the speakers are on, youtube sounds perfectly, and the avast sounds are activated).
Who else happens that avast no longer sounds. At least in my windows 7 do not sound neither threats nor full scans at all. And the sounds are activated in avast.
PS: This is in Avast Free 19.1.2360 (build 19.1.4142.0), with windows 7 professional 64bit.
The sound is silly but good, because the capture screens work well. And in fact for now everything works fine except for the sounds of Avast.