We moved here in 1994, the no-horn gates weren't installed until last year. Our house is 3 houses down the first street from the crossing. The blowpost for southbound trains stands 185 yards from our bedroom window (or so says my trusty Bushnell rangefinder).
I didn't mind the horns. It was kinda nostalgic. We had 37 trains a day, plus specials. The first couple of weeks we lived here it was annoying, after that we didn't even notice. Slept right through, even with the bedroom windows open.
With that said, I used to investigate crossing accidents for the old Southern Railroad. Your suggestion simply adds more electronics and more things to go wrong, plus a sign that nobody will read. Our almost-accident a few years ago was an idiot who drove around a large "CROSSING CLOSED" sign. We were walking our dogs when he drove his jeep onto the crossing - they had removed the asphalt to repave, and he drove right into the hole and his front bumper stuck under the first rail. About that time we heard the horn two crossings north . . . .
My husband dove into the Jeep and forcibly hauled the man out, while I hared home with the dogs and brought back our Expedition and a logging chain. Hubby was just hooking up the chain to the Jeep's rear bumper when the headlight came around the curve. Fortunately the engineer was under a go-slow order and brought his train to a halt about 50 feet from the Jeep. The engineer was cussin' mad, needless to say.
You can't fix stupidity.
The European gate does prevent anyone from jumping the crossing if the gates are working properly. But old Murphy hangs around railroad crossings a lot.
My house is less than 100yds from the track, about 100yds before a crossing. I'm not sure of the train's exact position when it sounds the horn, but it's loud.
Your suggestion simply adds more electronics and more things to go wrong, plus a sign that nobody will read.
The sign would be for the engineer. If an engineer cannot be trusted to read signage, he shouldn't be driving a train. I'm not sure I see a particular difficulty with designing the system so that in case of failure the light for the engineer would definitely not blink. And in that case if the engineer is doing his job he will sound the horn (if the engineer can't be relied upon to sound the horn if the light isn't blinking, how can he be relied upon to sound the horn in any case).
Our almost-accident a few years ago was an idiot who drove around a large "CROSSING CLOSED" sign.
How often would having the engineer sound his horn make any difference.