There are two versions of the Shouty Mobile Phone Man - one talks incessantly to his friends in a social capacity, the other talks incessantly to his work colleagues in a corporate capacity. Generally, it's a man thing. Both are major irritants on the daily commute, with the shared trait that they cannot function without a mobile phone - in fact they would rather lose a bollock than be without one for a nano second.

Social Mobile Phone Man - Gary
Gary talks loudly to ensure everyone in the carriage can hear that he actually has mates. He does this in an effort to make fellow commuters realise he's just the sort of man you would like to take down the pub. But really it's because there's no beginning to his talents. So instead he wants everyone to know he has a hugely exciting social life. He was probably one of those kids at nursery who came up to you and licked your face because he desperately wanted to be the centre of attention. He's witty, insightful and keeps his finger on the pulse of cultural developments. He wishes.

Generally his loud conversations mean that he's the last man on earth you would like to take down the pub or anywhere for that matter. Apart that is, from a torture chamber located in a terrifying autocratic regime somewhere overseas. He likes fellow commuters to share in his jolly japes from the night before, which usually involve too much alcohol:

"Yeah. It was a right laugh. Ha ha ha."
"Andy was blathered by 8. He stunk of cider even before we got to the King's Head. Ha ha ha."
"Did a crap on the pavement outside Asda on the way home. Ha ha ha."
"Nightmare. Ha ha ha."
"Wanker." and so on.

He measures his success by the number of headlights he has on his second hand BMW and apart from jolly japes, his favourite topic is footie. This generally includes a skilled analysis of which manager or player "is ****ing useless". Debates also rage about whether it was a "****ing penalty". He is completely partisan in support of his team and scathing about other supporters: "They only drink ****ing Prosecco at Arsenal" etc. However, all his mates agree no matter what their footballing allegiance that women shouldn't be referees: "It's not natural."

Gary is known to have the odd cultural conversation however. In a way it's a little miracle, when the latest world news inexplicably manages to find its way through to his consciousness. Witness his observations on the death of the fashion designer Alexander McQueen, which neatly exposes his homophobia:

"But how can you hang yourself in a wardrobe?"
"My hangers are all those metal bendy ones. He couldn't have used one of them."
"What?"
"Must be a bloody big wardrobe then."
"He wasn't like a real famous fashion designer though, was he?"
"He's not your Versace, is he?"
"He was ****ing gay though. Yeah. Poof."
"I think they all are."
"Maybe that's why they have big wardrobes."

When he's not speaking on his mobile phone, which isn't often, he needs to occupy himself with a game app. This is because his brain can't work on its own without external stimulation - his mind is like a lardy walrus that needs prodding with a stick to initiate a reaction, because to be honest the only thing he can really achieve on his own is dandruff. So when he's exhausted his phone contacts, it's on to Fruit Ninja or Commando Communist Cull on his phone. He can't sit still obviously, so during app playing he will bounce his lower leg up and down, while keeping his toes on the floor. I'm not sure, but believe this is a relaxing smoothing action for the testicles that negates the need to scratch around inside the trouser department.

How to spot a Gary
He will board the train with his phone to his ear, already speaking loudly. If he isn't in the middle of a phone conversation (very unusual or there's no mobile signal as yet), he'll have his mouth slightly open as he hasn't yet mastered the art of breathing through his nose. His hair will be cut reasonably short and be plastered in hair gel. He'll be wearing Lynx body spray just like The Hoodie, unaware that really it's for young teenage boys, and a crumpled, slightly shiny suit bought in a blue cross sale at Debenhams. He used to be fairly slim, but he now has the beginnings of a solid beer belly. The top button of his shirt will be undone and he will wear a tie with an unconvincing knot, and a small orange/green-y curry stain on the front. Sometimes the suit is worn in combination with a pair of trainers with a prominent Nike logo. This shows he is indeed a sporty man himself. After all he does play in the Second XI representing Crap Town United in the Apex Photocopiers County League Division 3.

Corporate Mobile Phone Man - Jeremy
Jeremy looks down on Gary, but really he's very similar, just has better annunciation and more A levels. Jeremy talks loudly to ensure everyone in the carriage can hear that he has a very important job that entails monumental decision-making involving fast sums of money. He usually works in finance (or possibly law). He has a high opinion of himself undisturbed by the facts. He therefore talks loudly and incessantly on his mobile in an effort to make fellow commuters realise he is just the sort of man who should head up a multinational company or be Prime Minister, it's just that no one has quite spotted his potential yet.

He believes his firm should pay for him to go first class on the daily commute. He has no sense of humour because he is married to a woman who was weaned on pickles and she has banished any sort of fun from his home life. 

Bullied at home, you just know he was bullied in the school playground too. Mostly for having sticky up hair, knobbly knees and no social skills. That's why he adopts the air of a bully in the workplace, employing a slightly more subtle version of the Alan Sugar management style:

"No Fiona, I said I want all the Heads of Department there on Thursday. We have the Russian contract to sign and I don't want any cock ups. Ah and book me a taxi to get me to my 4 o'clock in plenty of time, will you?"

His lack of social skills, fun and humour means he is reasonably detached from popular culture, believing that Puff Daddy is a dangerous snake and Caffe Nero is an Italian opera singer.
When speaking to his contemporaries as opposed to his minions, he makes sure we all know the difficult financial world in which he is such a big player, as these things are extremely important to fellow commuters:

"Hi, Alan it's me."
"How's it going with the Russian situation, dear boy?"
"Yes I know, but they just don't understand the complex nature of derivative bond NASDAQ premium dividend stock profit earnings ratio issues, at a time like this."
"Oh at least, £40 mil."
"Well, we could have an extension to the contract, with a sub clause for £5 mil and . . . . (carries on for another ten minutes)."

Yawn.

This bumptious approach doesn't work at home of course, as his wife looks like a short truck driver in drag, and has the same underlying air of threatened violence, which is only enhanced by her somewhat plummy voice. She has a fondness for light blue eye shadow, applied up to the eyebrows and has thighs the texture of muesli. Her friends all look the same and can occasionally be glimpsed of an evening in London, heading towards the theatre like a horde of John Lewis' skirted cattle.
She completely dominates him, despite the fact that he earns all the money and she's a lazy cow. He doesn't really like her and she doesn't like him either, but what are you to do? He gets his own back by secretly wearing her underwear to church on Sunday.

To minimise the hen pecking his domestic telephone voice is in sharp contrast to the one he uses at work. It's laden with fear of domestic retribution for something he doesn't even know he's done yet:

"Darling I'm on the fast train."
"Can you pick me up at the station darling? It'll be about 7.30."
A minute or two elapses as she moans about something utterly trivial.
"Oh dear. Of course."
"OK, I'll wait, it's a lovely day."
"Be in the car park. Lovely."
A minute or two elapses as she moans about something else that is utterly trivial.
"No, no sort the dog out, it's fine."
"See you then darling."
"Love you."

How to spot a Jeremy
Initially Jeremy is more difficult to spot as he doesn't usually board the train speaking on his phone. He fools people by being disguised as a normal person. However, he'll be carrying some sort of briefcase because he's deeply old-fashioned. He'll get out some papers his secretary has printed out for him immediately he sits down, and when comfortable out will come the dreaded mobile phone. He truly believes that no one on the train could have a job as important as him. He's quite annoyed that he's forced to sit next to commuters who must be lowly workers. It's all because of the recession and the moratorium on first class travel by the Head of HR.

Jeremy will be wearing a boring grey suit (or possibly dark blue) and plain shirt. Although reasonably new, both will look oddly crumpled. He does like to have a tie with a bit of colour, but isn't as daring as Jon Snow - his wife won't let him. His hair will be sticking up, something which hasn't changed since school.

Survival tips
Don't sit next to Gary or Jeremy out of choice unless you have been profoundly deaf since birth. If they perch next to you, get out an industrial sized pair of headphones and play Black Sabbath or Motorhead as loudly as you can to block out their telephone exchanges. It's the only way to cope. Failing that, lean over during one of their interminable conversations and say: "Excuse me, could you speak a bit louder, they can't hear you in the next carriage." This of course won't change their behaviour, as neither have a good grasp of irony, but it'll make you feel better and will elicit an appreciative smirk from your fellow commuters.