Presumably they would use something like an electrically propelled ducted fan (basically the first stage of a high bypass engine). The noise I imagine would be reasonably similar.
I think a hybrid approach with a high bypass turbo fan powered by an electric motor. The fan could then switch over to a https://newatlas.com/automotive/inside-out-wankel/ when at cruising altitude. Using biofuels, or carbon air capture, we get long range and a closed carbon cycle.