In the past I did a post about how big vacuums where an instant trigger for me and the possibilities of why that might be and how to prevent them. Well since then I've tried just about anything I could think of, sound protection, mask for dust, shoes and gloves for vibration, and still didn't have much luck. Well the other day I had a migraine and was using the weatherX migraine ear plugs (that help with pressure) and had to use the vacuum, and I didn't up with a worse migraine. Not sure if it was the ear plugs or the fact that I already had one but it made me wonder, how much do big vacuums change the air pressure around them? Could that even be a possibility?