At the December premiere of the Chinese-dubbed 1957 Billy Wilder classic Witness for the Prosecution in a Shanghai cinema, dubbing artist Qiao Zhen voiced a more immediate mystery: “Do you still enjoy Chinese-dubbed films?”

When audience members, mainly nostalgia-seeking fans, responded with applause and shouts of “Yes!”, the 83-year-old veteran became emotional, offering a moving defence of his art form.

“Several years ago we felt this profession had fallen into a low point,” he told the...