Prince William experienced the piercing din of a vuvuzela at close range during the latest stop on his African tour.
The 27-year-old was visiting the Coaching for Conservation project in the town of Maun, in Botswana, when he was handed one of the plastic horns.
After failing to make a sound, William was forced to block his ear when he was out-blown by an 11-year-old boy.
World Cup teams have complained about the vuvuzelas which are blown by fans throughout the games in South Africa.
The horns, which first appeared at sporting events in the early 1990s, have been found to be louder than a drum and a chainsaw when played close to the ear.
When William was handed the horn by Rebaone Badubi, the prince said: "I can't blow it... OK, I will give it a go."
Then, after barely making a sound, William said: "There you go - embarrassed myself again - it's all good."
Rebaone then showed him how it should be done.
William and brother Harry are on a six-day tour - their first joint overseas royal trip - and will spend time visiting a number of charities they support in Botswana, Lesotho and South Africa.
On Wednesday, William saw youngsters taking part in Coaching for Conservation (C4C), a project which combines football training and wildlife protection.
Children were divided into groups named after animals known to work well in teams, such as wild dogs and hyenas.
Also on hand to witness the skills practice was retired South African footballer Lucas Radebe.
Speaking at the event, William said: "Sport gives us a sense of purpose and belonging through being part of a team.
"These qualities are shared by the extraordinary creatures around us, particularly here in Botswana.
"The wild dogs who work as a team and can run rings round even the best organised defence in the World Cup - even Germany's.
"The slowest cheetah that ever lived can beat Ronaldo to the ball. The impala's awareness and agility makes even Lucas Radebe's awesome dribbling skills look, well, rather like mine."
William volunteered to go in goal and try to save penalties taken by some of the children - most sailed past him into the net.
But the prince was almost upstaged by US singer Joe Jonas, part of the Jonas Brothers group, who was also visiting charity.
He gave a brief performance - to screams from local teenage girls - and one, Megan Butler, 16, admitted afterwards: "I like Prince William as well, but I was more excited about seeing Joe."
William was later shown around the Laboratory for Wildlife Chemistry, run by the Botswana Predator Conservation Trust, where he was told how chemicals gathered from animals were being analysed to understand more about their behaviour.
The two princes will link up again in Lesotho before heading to Cape Town to watch England's World Cup match against Algeria on Friday.
Football Association president Prince William will also be promoting England's bid to host the tournament in 2018.