When you hear a person sing, and their voice is so beautiful that they suddenly become extremely attractive, even if you didn't think so before. This is applicable to women or
men with sexy voices, even though sirens are technically
female.
This phenomenon is named after the lusty, half-bird, half-woman sirens of Homer's "The Odyssey." They beguile sailors with their seductive serenading, only to bring the poor individuals to their deaths. The siren effect uses singing to deceive (albeit unintentionally), having the potential to give
average-looking persons a façade of sexiness, "luring" others in.
For instance, this is the reason (or one of the reasons) the Phantom in all
musical productions of Andrew
Lloyd Webber's "The Phantom of the Opera" always manages to be sexy.
Broadway Fan 1: "Oh, my God, Ramin Karimloo is so sexy, even when he's playing a deformed man!"
Broadway Fan 2: "I completely agree, and the siren effect just adds to it. That voice is so seductive!"
Person 1: "Man, Sarah Brightman is so beautiful!"
Person 2: "I
don't know, man. I think it's the siren effect."
Person 1: "Well,
maybe it's both."
Student 1: "You know, I never found Matt that attractive before, but then I heard him sing. I think I'm
in love!"
Student 2: "I know, right? It'
s a perfect example of the siren effect."