Any solid lifter, meaning flat tappet or roller requiring a lash setting you will hear the lash being taken up when it’s running, but only if you know what you’re listening to. Any engine with a somewhat louder exhaust you will not hear a thing. Yesteryears mechanical grinds were much noisier, also having to keep up on lash settings, not so with today’s parts.  Don’t let anyone tell you that you will always have to be adjusting the valves, that’s an old tale from the past. With a quality set of roller rockers along with poly locks once you set lash properly (hot) you shouldn’t have to touch them for lengthy periods of time. I have run a mechanical flat tappet cam from Crane in my big block Chevelle for 25 years, and I haven’t had the valve covers off in years, also run a huge mechanical roller in my alcohol dragster and although I routinely check my lash, nothing ever changes. For proper adjustment, adjust the intake when you see the exhaust begin to open and adjust the exhaust when the intake is halfway closed, this way you are totally on the base circle of the lobe that you are adjusting.