Why do people shout on their cellphones?

About this episode

<p>How does traffic jam? And, why do some people shout into their cellphones in public places? Two subjects guaranteed to annoy even the most patient listeners.</p><p>The Phantom Jam Listener Matthew Chandler wrote to us: "I travel on the motorway for work and often I find myself sitting in a traffic jam for ages, thinking there must be roadworks or an accident ahead, then suddenly the jam mysteriously disappears to reveal… nothing! There's no apparent reason whatsoever."</p><p>Doctors Rutherford and Fry discover the cause of these phantom jams. Adam ventures on to the M25 in search of a tailback, and Hannah looks at projects around the world designed to thwart traffic tailbacks.</p><p>This case features Neal Harwood from the Transport Research Laboratory and BBC technology reporter, Jane Wakefield. Plus a special guest appearance from Greg Marston, aka 'Masdar City Man'.</p><p>The Aural Voyeur Listener Daniel Sarano, from New Jersey, asks why people shout on their mobile phones in public: "I have no interest in hearing about people’s private lives. I don’t enjoy the aural voyeurism. If people want to say 'honey I’m running late, be home in 5'. That’s OK, but discussing business or, worse, personal details…. I hate it. The whole idea would have seemed an anathema to older generations. I think they would have considered it rude to talk loudly in public. No sense of that in the 21st Century.”</p><p>We discover the answer to this annoying modern habit by delving into the inner workings of telephony. What follows is a tale of engineering rivalry, Victorian etiquette and early otolaryngology. Providing the answers are acoustic technologist Nick Zakarov and historian Greg Jenner, author of 'A Million Years in a Day: A Curious History of Daily Life'.</p><p>If you have any everyday mysteries for the team to investigate using the power of science, please email <a href="mailto:curiouscases@bbc.co.uk">curiouscases@bbc.co.uk</a></p><p>Producer: Michelle Martin</p><p>Image: A man on a phone, Credit: Thinkstock</p>