Is it normal to have oxygen leak from the cannula? When I put on a new cannula, I cup my hands around my nose to see if I can hear the oxygen; if I can, I won't use it because I believe I'm not getting all the oxygen I should. Is this correct or is it okay to have oxygen leaking from the cannula? I end up throwing away a lot of the cannulas because of the noise so I thought I would ask and see if someone knows the answer. Thanks.