Sometimes he communicates using an electro-larynx, a small device whose vibrations produce a synthetic voice.
When that becomes uncomfortable he resorts to writing on paper, letting an assistant read out his instructions.
"Sometimes a look is enough to put across what I want to say," he says.
But on the pitch, hand signals are key.
"I use sign language to tell the players what to concentrate on during training and matches," he says.
"The key thing I have to tell them is not to argue with the referee. When I raise four fingers on one hand it means they need to press the opponent -- they understand that well."
Throughout training sessions and matches, he issues instructions with his arms, one gesture after another.
He opens his arms wide and the players spread out across the pitch. He reduces the gap and they adopt a more compact formation.
He raises two fingers on one hand and one on the other: two against one, the players mark their opponents.
- Money problems -
Coaching the Air Force Club youth team since 1998, Flayeh has become one of the most popular coaches in Iraq.
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Local media call him "the star scout", a name he has earned by training up some of the top names in Iraqi football.
But that has not prevented the club from facing financial crisis.
"The players have continued their training without getting paid and I haven't received my salary (about $400, 380 euros) for two months because of the club's financial situation," he says.
Last year he was forced to sell his car and some personal belongings to finance his laryngectomy in Beirut.
To restore his voice, he would need a $50,000 (47,000 euro) operation in Germany -- but he says that is beyond his means.
His former players have launched a fundraising campaign to help finance his operation. So far they have managed to raise $3,500.
But players say the club's financial difficulties and Flayeh's illness have strengthened the relationship between the young recruits and their coach.
The Air Force Club's youth team, which won the local championship this season, is a training ground for many players who graduate to the club's first team, which won the Asian Football Confederation Cup in 2016.
His players call him "the inspirer".
"We have no difficulty understanding what he wants, on the contrary we have started to quickly understand his signs," says Sadiq Binwan, a 17-year-old on the team.
"We are happy when he raises both fists -- it means he is satisfied with us," he says.
"Our trainer's patience with his health problems and his determination to work increases our determination too, and it makes us want to tackle all the obstacles the team is facing."