Changing your tyres for identical replacements would likely have no effect on ride comfort or road noise, so to achieve these improvements you would need to select a different tyre. Looking on blackcircles.com you can choose your tyre size and look for tyres that have a low noise rating. Additionally you can choose a tyre with a taller sidewall - the fourth and fifth digits of the tyre size indicate the aspect ratio, so a tyre with this number increased by five would give you a taller sidewall with a small increase in ride comfort while still fitting on your existing wheels. It is worth bearing in mind that this may also result in a slight reduction in steering response in terms of handling, as the taller sidewall will deform to a greater degree during hard cornering.