Zinc Air hearing aid batteries use air as an energy source, and the tab seals the air holes on the battery. Once the tab is removed, it takes approximately two minutes before the hearing aid battery is activated/charged. At that point, the battery compartment can be closed. If not the battery can in the worst case be damaged and will not come back to normal Voltage level needed!
Please remember not to remove the tab before the hearing aid battery is to be used. Reattaching the tab will not prolong the running time of the battery.