Women are turned on by men who mumble as it makes the sound more masculine, scientists have found.

Marlon Brando

Marlon Brando

Hollywood stars such as Marlon Brando and Tom Hardy have been accused of mumbling their words on the screen but the study found that it is attractive to the opposite sex.

However, men find more precise pronunciation attractive in a woman as they believe it shows femininity.

Dr. Daniel Stehr, from the University of California, recorded 42 people - 21 male and 21 female - speaking short sentences and then asked 124 new participants to judge how attractive the voice sounded after listening to the audio.

He said: "From a sexual selection standpoint, males with traits that are slightly more masculine than average are typically preferred.

"In this context it would make males with less clear speech more attractive."

Stehr added: "Vocal traits can be relevant cues to attractiveness - a likely outcome of the forces of sexual selection."