20-Year Prospect
Did you have a deaf grandfather who liked to scare the bejeezus out of you when you were a small child by making his hearing aid screech at you? Well, we did, and we attribute the resulting childhood trauma to Grandpa's audiologist.
This career field will be around as long as there are old folks to yell, "Eh? Eh? What'd you say?" at all their pals in the nursing home...so, basically, until the end of time. See, about half of people over the age of seventy-five have hearing issues; same thing goes for about one in three people aged sixty-five to seventy-four (source). Must've been all that death metal they listened to back during the Great Depression.
But it isn't just the elderly who're plagued by hearing problems: Some 12,000 kiddos are born in the United States every year with hearing-related birth defects (source). Many of these defects can be overcome with proper treatment and therapy...but an audiologist has to catch the defect first.
So, yes, audiologists will still be around in twenty years, giving old men the instruments of torture they need to terrify young whippersnappers.