I get no sound. After reinstalling Stretch a couple of months ago, the computer is silent.
May be completely unrelated...
Since upgrading to the 4.16.16-2 kernel, anytime I reboot my PC I boot into a soundless environment, with my sound system reporting my sound device as the "Dummy Sound Device" (or something similar). I can "sudo kill [timidity's PID]", and that's restores my sound.
As I understand it, Timidity is taking exclusive hold of some audio file (/dev/sound ?) early in the boot process which prevents other apps (Pulse, ALSA, etc) from using that file.