I have long noted that local radio advertisers ALL exhibit speech defects of one sort or another as well as being grammatically incompetent. The national advertisers mostly are just grammatically obtuse. My favorite is several ads for a chiropractic clinic. They are spoken by a female or a male voice and both have a severe problem with S. All their S sounds are exaggerated, some to an extreme. He sounds as if he is trying to get over an inability to make the sound at all. I called a health food place because the use of “for” instead of “of” reversed the meaning of what the fellow was trying to say. I was gratified that the next time I heard the ad, it had been fixed. That speaker was an immigrant, though, and actually interested in getting it right.
Then there is the Culligan Water Treatment ad. The lady says that since her water filter was installed, “I don’t have that smell, anymore...” The implied claim is interesting.
A speech defect can indicate that the person went to a private or parochial school. The public schools have speech therapists who go around and listen to every kid talk.