Yeah just slapping a suppressor on something will still be car horn loud.

But the right combination of silencers and subsonic ammo can still have a huge reduction to bystander perceived noise. Decibels are an exponential scale, so whilst even just going from 160 to 120 dB at the muzzle doesn't sound like much, that's a 99.99% reduction in pressure wave amplitude. Across the street it could sound about as loud as someone thwacking two drumsticks together. To even just the next street on the block it could just sound like general city background noise.

Yeah just slapping a suppressor on something will still be car horn loud.

But the right combination of silencers and subsonic ammo can still have a huge reduction to bystander perceived noise. Decibels are an exponential scale, so whilst even just going from 160 to 120 dB at the muzzle doesn't sound like much, that's a 99% reduction in pressure wave amplitude. Across the street it could sound about as loud as someone thwacking two drumsticks together. To even just the next street on the block it could just sound like general city background noise.