How can I wear a hijab if I wear hearing aids, because I need access to my ears in case the hearing aid battery dies or I need to change its settings? I don't want the hijab to potentially block the microphone on the hearing aids because it might affect my hearing.

You can wear the hijab in a way that does not cover your ears. According to a Saudi fatwa this is permitted for someone who needs hearing aids.

Source:

• Saudi fatwa (Arabic PDF)