In Chapter 17, after Rick and Rachael have sex and he decides not to kill her, they listen to the radio in the car. Oscar Scruggs, the man on the radio, speaks in a dialect that Rick disparages with verbal irony:
The radio said, “—ah jes wan ta tell ya, folks, that ahm sitten hih with my pal Bustuh, an we’re tawkin en havin a real mighty fine time, waitin expectantly as we ah with each tick uh the clock foh what ah understan is the mos important announcement of—” Rick shut the radio off.
“Oscar Scruggs,” he said. “The voice of intelligent man.”
Oscar is a frequent guest on Buster Friendly's radio show. He speaks in what appears to be an exaggerated Southern drawl. Rick can't bear to listen to Oscar's voice in particular. "The voice of intelligent man," he scoffs, meaning the opposite. He thinks Oscar's dialect sounds unintelligent and uneducated.
Rick's disgust with Oscar seems to be heightened because of what has just happened with Rachael. As an android created by humans, she should not be more intelligent than humans. And yet, she has just explained that she has outsmarted Rick. She manipulated him into having sex with her so that he would be unable to bring himself to kill her. Disgusted by Rachael's cold smugness and embarrassed that he fell for her scheme, he tries to save face for humanity by turning off the radio and asserting that he knows Oscar sounds unintelligent.
Rachel immediately turns the radio back on. Rick does not realize at the time that Rachel wants to listen to the radio show because Buster Friendly is going to unmask Wilbur Mercer as a sham. Even so, he correctly clocks her glee at staying one step ahead of her human rivals. He watches her bitterly as she listens to the radio and revels in her sense of superiority.