It's a profession that a large majority of the population won't ever notice, but being a sign language interpreter can make a world of difference to a group of people who tend to go un-catered to and unnoticed.
Over 1 million people in the United States are considered "functionally deaf," and it's a condition that carries a lot of hardship with it. Our world as a whole isn't designed well for those who aren't able to hear (or see or speak for that matter), and those suffering from deafness have to essentially reshape their entire lives to accommodate.
One of the biggest elements of this is the learning of sign language, which has been a standard of deaf communication for decades now. While different countries use different versions of it, it's still been an instrumental aspect of deaf life worldwide, and the learning of it means that there's now a way for people who can't hear to understand live speech.
In the spirit of this, new conferences and major public speaking events often hire sign language interpreters to provide a solution for deaf people in the audience. However, the deaf community has recently been quite frustrated, as more than a few news organizations have been allowing completely untrained, often fraudulent interpreters onto the sets of their conferences...