Two hearing aids? Left has blue marker and right has red marker, remember red for right.
Hearing & Ear Protection From Pressure Exposure
Familiar with the sensation of going up a hill or up in an aeroplane and your ears starting to pop? Due to the pressure difference of your middle ear and a change In the pressure external to your ear this causes a need to equalise your middle ear pressure. If you are exposed to pressure regularly this page will have some helpful tips of what to do and avoid.