Most job candidates know to dress nicely for Zoom interviews and to arrange a professional-looking background for the camera. But a new Yale study suggests they also ought to test the quality of their microphones.

A tinny voice caused by a cheap mic, researchers say, could sink their chances.

Through a series of experiments, the study demonstrates that tinny speech—a thin, metallic sound—during video conferences can have surprisingly deep social consequences, leading listeners to lower their judgments of a speaker’s intelligence, credibility, and romantic desirability. It can also hurt an individual’s chances of landing a job.