It’s a type of ad that the Clinton campaign has made more than once.

John G. Geer at Vanderbilt University and I have been gauging the effectiveness of this and other political ads by asking randomly assigned groups of people to react to and evaluate them all year. (The project is called SpotCheck, and you can watch all the ads we’ve tested and see how people rated them here.)

We’ve tested dozens of campaign ads aired by or on behalf of the two major party candidates since June. The viva voce ads stand out in a few ways. More people (57 percent) say these ads are memorable compared with Mrs. Clinton’s positive promotional ads (only 45 percent). Similarly, 54 percent of those randomly assigned to see ads like “Mirrors” and “Role Model” view them as truthful, while only 37 percent believe this about the promotional ads.

Fewer people say the ads using the candidates’ voices make them feel happy (21 percent vs. 49 percent) and hopeful (30 vs. 54) when compared with the promotional ads, and more say they make them feel angry and worried. Almost 75 percent of the people who saw an ad with Mr. Trump’s own words said the ad made them feel angry. Only 43 percent of those who saw one of Mrs. Clinton’s promotional ads felt this way.

Despite this recent use of the genre, ads that use only an opponent’s recorded audio for voice-overs are rare. The Clinton campaign has used Mr. Trump’s own words against him several times. A similar voice-over ad called “Role Models” ran during the conventions and showed images of children watching television as Mr. Trump is heard saying: “I love the old days. You know what they did to guys like that when they were in a place like this? They’d be carried out on a stretcher, folks.”