As you can see from the graph, an asphalt roof (Roof A) is technically quieter than the 2 steel profiles (Roofs B, C, D, E) we tested but only marginally and we must note that most humans cannot distinguish between sounds that are 5-8 dB apart. Installing a steel roof over a solid deck with a good underlayment, and with an insulated attic airspace below, makes it easy to control the noise.
For more information on the study, see our Fact Sheet #50.