I don't care what the numbers say, there is no comparison. I went a few years ago and you NEEDED ear plugs. I didn't take any thinking "bah, I've heard race cars before, I won't need them". I was f*cking wrong and luckily I was able to get some at the track.
They had one old V8 there (RB7) doing the ultimate speed comparison and even just that one running was borderline on wanting to block your ears, but with all 22 of the new ones running you don't even get close to needing them.
dB is a logarithmic scale so a change of 10-15 is significant. But it's not just the volume but the nature of the sound, the old ones sounded just glorious while the new ones sound... agricultural?