She has undergone frequent reinventions to keep herself looking youthful.

And it seems Madonna may have taken a similar approach with her voice, too.

Linguists who analysed four decades of interviews found the 68-year-old singer’s voice doesn’t follow the patterns normally expected in older women.

When women go through menopause, the muscles around their vocal cords lose elasticity, making their voice sound deeper.

But the experts say it is surprisingly difficult to estimate Madonna’s age from speech alone.

They suggest her youthful-sounding voice is the result of a deliberate effort to control how she is perceived.

‘Our study shows that Madonna’s voice appears younger than her age,’ linguist Anna Bothe Jespersen, from the University of Copenhagen, said.

‘Her pitch does not follow the patterns we would normally expect from a woman in her 60s, and the way she pronounces a number of vowels does not match the speech patterns typically associated with either her generation or the places where she has lived. 

‘In other words, her voice is difficult to place both in terms of age and geography.

‘We argue that this is a deliberate strategy, with the voice supporting an image of a youthful, attractive and globally oriented performer who is not constrained by chronological age.’

According to the researchers, the development of Madonna's voice is consistent with the carefully crafted visual identity she has maintained throughout her career.

Each album release and concert tour has been accompanied by a new age-defying look, and the findings suggest she may have managed her voice just as deliberately.

‘When it comes to pitch, one particularly striking feature is how much her pitch varies over time,’ Dr Jespersen said.

‘Women's voices generally become lower after menopause, and we do observe a drop around 2013, when Madonna was 55 years old, which roughly corresponds with the timing of menopause.’

But rather than continuing to deepen, Madonna's voice appeared to become higher-pitched again shortly after.

Researchers suggest this could point to a conscious effort to maintain a more youthful-sounding voice, although hormone therapy during menopause may also have influenced the change.

Even so, neither explanation completely accounts for her unusual vocal evolution.

‘Throughout the 40-year period we studied, it was remarkably difficult to estimate her age based on her voice alone,’ Dr Jespersen explained.

‘We observed multiple rises and falls in pitch. In fact, some of the lowest pitch values occurred during the 1980s, when she was young, while her voice has generally become higher since the late 1990s.’

And just as Madonna's overall pitch proved difficult to categorize, so did her pronunciation of several vowels.

‘Madonna's vowels do not follow the pronunciation changes typical of either her own generation or the regions where she has lived, such as Michigan, where she grew up, or New York, where she spent much of her youth,’ Dr Jespersen said.

‘In fact, it is almost impossible to identify a geographical origin from her pronunciation.’

Analysis of the way Madonna pronounces words such as ‘trap’, ‘dress’, ‘kit’ and ‘thought’ showed that she produces several vowel sounds farther forward in the mouth and with greater distinction.

Research suggests this type of clear, fronted vowel pronunciation is associated with youthfulness, attractiveness and sex appeal.

‘These are qualities that Madonna has likely sought to project not only visually, but also through her speech,’ Dr Jespersen said.

According to the researchers, who published their work in the Nordic Journal of English Studies, the study reflects a broader cultural shift in how age and ageing are understood.

Increasingly, ageing is seen not merely as a biological process, but as something individuals can actively shape.

‘People can use appearance, language and voice to influence how others perceive them throughout their lives,’ the team concluded.

‘Madonna is a particularly interesting case because she has consistently challenged expectations of how women should behave and present themselves as they grow older.’