iPhone 5s Hearing Aid Compatibility
If you wear hearing and experiencing problems with the iPhone 5s, you should know that by default the iPhone 5s didn't enable hearing aid mode. Here are the instructions from Apple:
Activating hearing aid mode in the iPhone 5s
To activate Hearing Aid mode on iPhone 5 or later, go to Settings > General > Accessibility. Hearing Aid mode on the iPhone 5 modifies the phone?s acoustic settings to improve compatibility with hearing aids set in "T" or telecoil mode.
This obviously works best for those that have hearing aids with a telecoil mode. Most newer hearing aids have Blue Tooth so the connection is slightly different and the above settings doesn't apply to you.