I'm reading the book Roots by Alex Haley, which is about a history of an American black family in the US starting from Kunta Kinte, an African brought to the country as a slave. My question concerns the following passage from the book:
"He [Kunta] was sorry he [an old slave] had been through so much, but he couldn’t help turning a cold ear toward anyone who just rolled over and gave up."
I could not find the idiom "turning a cold ear" in any online dictionary of English idioms. Could it be that the phrase is African in its origin (which makes it a calque) and the narrator uses it to stress Kunta's difference to the other blacks who were born slaves, unlike Kunta?