explain xkcd:Editor FAQ
For example, everyone knows that when you go Sonus Complete to the movies the sound can be very loud. Because of this, a problem can be caused for someone with a hearing aid that is set on one level that isn't able to be changed. The sound may be too loud to the point of irritation. If this were to occur, the person would not really be able to enjoy the movie. So, by having an adjustable device, they are able to turn it down or up at will.
This type of device is also helpful in sports arenas. These places can be even louder than movie theaters. That is because the sound isn't just coming from a big screen, but there are sometimes tens of thousands of people in one building talking and cheering, many times at the same time. This can be too much for anyone, but especially someone who is wearing hearing aid that is set on a high level. So, it's wonderful that there are devices where people are able to control the volume for themselves.
The desire to turn down loud noise can also be something that happens at a restaurant. At a restaurant everyone is talking or laughing and having a good time. So, it's advantageous for to be able to adjust the sound accordingly. On the other hand, there are some eateries that are quieter and more laid back. So, someone may actually need to turn the volume up to hear better instead of leaning on the table almost knocking over their drinks or leaning into their food. They can turn the volume up on their hearing aid and it will allow them to hear the person sitting across from or next to them much better.
