Recordings from the early twentieth century have been extensively analysed by students at Uttoxeter University and compared to recordings over the intervening years. There have been several remarkable discoveries, including the fascinating fact that men are less hairy now than one hundred years ago, and that men are definitely taller.
The most remarkable discovery is that men's voices are getting a higher pitch.
"We listened to hundreds of recordings of men from all walks of life," said Mani Fold, who was running the study. "As the years go on, the voices get higher pitched. It's quite clear."
According to Fold, men from the Roaring Twenties would have given Barry White a run for his money in the baritone stakes, whereas men from the Twenty Twenties are expected to sound like Minnie Mouse.
"We don't know whether men are approaching their natural tone," said Fold, "and that people from the previous centuries had their voices affected by pollution and stuff. Or perhaps modern pollutants are causing the increase in pitch. We're pretty certain it has something to do with pollutants though."
Simon Nomer, of the Film Archive Restoration Team has also looked at the same footage.
"This is why you should not let scientists answer questions about film," said Nomer. "They are right in that it has something to do with pollution."
According to Nomer, men are no more high pitched these days than one hundred years ago. Instead, pollution affects the sound tracks of old film footage.
"All the women sound like Mariella Frostrup, they didn't consider that did they?" said Nomer. "Pollution does some funny things to old movies."