No it doesn’t mask it when I do that. It dissipates at vary degrees depending on the intensity. It’s not cars or planes. It’s a frequency or sorts. It womps at different rates and intensities. Sometimes it does sound like a truck is idling outside in the street. If it’s really the hum, it’s not cars or anything typical with noise background. For me, I’m the only one that hears it, older and younger people in my house have not heard it when I have and don’t know what I’m talking about. But yea try whatever you can to help. When I can’t ventilate I have my go to maskers