DAN156,
Try the A340 for size; quitest aircraft I ever had the oppertunity to pax in. Sat next to engine 3 and during cruise the only noise heard was ..... the aircon.
And noise is so very dependent on where you're sitting. Take the MD80 for example. Up the sharp end you hardly hear the engines start and during t/o they still only produce a distant roar. However, move down to the last row and be seated next to those JT8D's and it's a completely different story.