His teachers even complained that the 7-year-old was disrupting class with his whistling.
It wasn't until doctors put a camera down his throat and found this was no laughing matter.
It wasn't a sound effect, it was actually a whistle stuck inside Hector Flores, Jr.'s lungs.
Nearly a month ago, the boy was playing in a pool when he swallowed a part from inside a plastic toy duck that makes that whistling noise.
Two weeks later, his mother noticed the strange sound when the Bronx boy had a laughing spell during a shopping trip.
"I said, 'Did you whistle?' 'Yes mommy I whistled.' A man at the bodega said the boy whistled," his mother said.
So, his parents took hector to the emergency room at Bronx Lebanon Hospital.
"They said he didn't have anything. That it was probably a psychological issue with the child. They concluded the child had a lot of fecal matter," his father said.
They were given pills for a digestive problem.
Still worried, his father recorded the whistling and showed the video to doctors at Montefiore Hospital who the used a camera to find the whistle in his respiratory system.
Doctors performed a simple 45 minute surgery with an endoscopy.
The whistle was in one of the arties near his lungs.
Hector's parents say this is proof to always follow your parental instincts.
A Montefiore spokesperson confirms the boy was a patient but couldn't go into specifics.
A Bronx Lebanon spokesperson says the hospital is also aware of the patient and that it gets upwards of 130,000 visits a year and takes pride in its services any concerns will be fully investigated and address.
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