Men might want to start mumbling like Tom Hardy if they want to be successful on a date, a study suggests.
Researchers in California have found men who mumble are seen as more attractive by women.
Speaking less clearly – like Hollywood legends Hardy and Marlon Brando – is seen as attractive by women because it is linked to being macho, it's claimed.
Men, on the other hand, find clear pronunciation – such as Elizabeth Hurley's refined tones – attractive in the opposite sex because it indicates femininity.
Women tend to produce speech that is 'acoustically and phonetically more distinct' than that of males, the study authors claim.
Tom Hardy in the 2018 film 'Venom'. Mumbling like Hardy in his films might be something of a turn-on for women, a study suggests
Some animals show high levels of sexual dimorphism – meaning they show big differences in their physical characteristics aside from their sexual organs – partly to attract mates.
For example, in peacocks, males are normally brightly-coloured with large lustrous tail feathers, compared with the female, which has more subdued colouration.
Other examples of sexual dimorphism include antlers that are largely only found in male deer and the striking mane of the male lion.
Attractiveness in speech patterns appears to be a form of what's known as 'sexual dimorphism' – a strong difference in any characteristic between the two sexes other than the sexual organs.
'From a sexual selection standpoint, males with traits that are slightly more masculine than average are typically preferred,' said study author Dr Daniel Stehr at the University of California, Irvine.
'In this context it would make males with less clear speech more attractive.'
Hollywood hearthrob Marlon Brando was given the nickname 'Mumbles' by his Guys and Dolls co star Frank Sinatra.
The Oscar winning legend famously put cotton wool in his mouth while playing Don Corleone in The Godfather to make himself less intelligible.
Other leading men who have been accused of mumbling on screen include Jeff Bridges and the late Heath Ledger, as well as Tom Hardy.
One of Hardy's most unintelligible vocal performances was in the BBC series Taboo.
At the time, one fan tweeted: 'Tom Hardy in Taboo; his voice is sexy even tho I can't understand a word he says without subs [subtitles].'
The Hollywood Reporter, meanwhile, ran a 2018 article on the British actor, entitled 'Why Tom Hardy Can Be So Hard to Understand'.
But this new study suggests women actually like mumbling, contrary to popular belief, after they identified a 'sizeable gender difference' in speech intelligibility.
Pictured, Elizabeth Hurley in 'Bad Boy' (2002). Hurley is known for speaking the Queen's English during her film career
'Much received wisdom and many vocal coaches would encourage people to slow down and carefully enunciate to make a better impression on their audience, said Dr Stehr.
'However, when it comes to empirical studies of how attractiveness of the human voice is judged, we couldn't find previous work investigating whether an actual link exists between perceived attractiveness and overall clarity of articulation.'
For the study, the researchers recorded 42 individuals performing various speech tasks and used separate pools of participants to rate vocal attractiveness of the recorded talkers.