You have no idea how happy I am to find that I’m not the only person having a tough time with the blow/hum! I had to try several times in a 100+ degree car yesterday (my first day), with a parked cop staring me down. I’ve found the blow part to be fairly easy but the hum is messing with my head. I tend to either stop blowing when I transition to humming, or I transition okay but run out of breath before the test is over. Has anyone found another sound besides “whoooooo” that works?