It's not removed, it's just moved behind a specific toggle. I suspect its one of two things: 1) It's part of parental controls. You can disable in the parental

It's not removed, it's just moved behind a specific toggle. I suspect its one of two things: 1) It's part of parental controls. You can disable in the parental controls the ability to turn off "loud noise reduction", it's possible that since setting to the off mode also disables this, that the toggle exists so that the off mode can be removed from the mode list as well with this restriction in place. I can't validate this because that parental control does not appear to be something you can enforce on your own device when you're the "parent" 2) The medical certifications for the hearing aid functionality require that the device can not be accidentally placed in a state where using the device as "intended" can cause further hearing damage. By placing the mode which disables hearing protection functionality under a separate explicit toggle with notes about what that does, it satisfies the requirement while still allowing the use of the mode.