I have hearing loss, as many of my friends and acquaintances do. Frequently when traveling, we encounter situations that have the potential to place us in grave danger, and cruise ships are no exception to the rule.
One point that has been brought up consistently in different situations, is the willingness to provide some kind of accommodation, whether it is the right one or not. For example, when traveling, some of my friends have been offered a wheelchair when they request assistance, or they might be offered one of the few wheelchair equipped rooms. Others have been offered sign language interpreters, when they do not know sign language, nor do about 90+% of the people who have hearing loss. As genuine as these accommodations are, they are being offered erroneously to people who cannot benefit from them. These accommodations should be available for those who need them - without having to book a cruise a year in advance, and I agree with comments from other people who say that there should be some need demonstrated in order to book these physically accessible rooms in advance.
Universal accommodations that can help everyone should be in place, such as lighted signage, captioning (which benefit not only people who can't hear, but in situations where the surrounding noise is too loud to hear sounds), flashing and vibrating alerts. Other accommodations such as amplified or captioned telephones, assistive listening devices (a loop system works very well without as much equipment needed) should be available as well.
It would be worthwhile to have people who are extremely familiar with accommodations for each type of disability review available accommodations prior to a ship being placed in service. Captioning on any visual type of communication, such as ship announcements, shows aboard ship - whether live or video, tv, or movies, should become routine. Physical accommodations for those with mobility problems should be routine, and the number of accessible rooms should be increased.
These types of accommodations benefit people with disabilities who need them, but they also provide unexpected benefits for other people as well. It just makes sense to make cruise ships accessible, and those who need the accommodations will find them when they need them.