I posted this question in the A13 Beta 4 thread but didn't got any feedback, so post it as a separate question to see if someone can help.

I switch to A13 since beta 2 and just updated to beta 4, everything seems run smoothly. However, I just found out that my "Google Assistant" lost the "beep" sound! What it means is that if I say "OK, Google" or "Hey, Google", I can carry out to give the command or instruction as I want but I am losing the "Ting" sound of the reaction once I say "OK Goolge" or "Hey Google". It's not really a big deal but just gave me a funny feeling as I would have to look at the phone screen to see if Google Assistant really working. All I can say is that I don't know when this is started as I didn't use Google Assistant for quite a long time, but it is definitely working when my P6P was on A12.

Can't someone confirm if this is just me or if there is a setting I can get this "beep" sound to come back. I play around with the phone for a couple hours and couldn't figure out any setting in "Google" app, "Assistant" app and system sound to have this be related.