One of the greatest misconceptions amongst those not familiar with soundproofing is that insulation can effectively block sound.
Let’s clarify this point. Insulation can act as a soundproofing material, but only in the sense that it slightly dulls the noise you are trying to block. The pink insulation that goes inside your walls during construction will never stop sound as well as a real soundproof product.
Sure, you need insulation to keep your house warm, but if you have a sound problem you’re going to need something more.