A Wellington audiologist is warning that noise levels in our environment are dangerously high and particularly impact children.
One in 10 New Zealanders used to suffer from hearing loss - now it's one in four.
Johnathan Gasson, 10, has auditory processing disorder, which his mum Liz says can present as deafness.
Loud noise causes him distress and anxiety. He wears hearing aids connected to a microphone to help him cope in a large class at school.
"Most people have been commenting saying the noise is noisy because there's 90 children in my classroom," he says.
Audiologist Lisa Seerup is concerned about growing class sizes.
"When you get these 90 kids in a classroom, you can't help but exceed safe noise levels."
By "safe" she means noise exposure for children shouldn't exceed 70 - 75 decibels, as that's when damage is caused.
Above 50 - 55 decibels can cause difficulties in learning.
"That causes not only learning disabilities or the inability to learn, but sensory neural hearing losses and neurological damage of the ear," she says.
Peak levels in some early childhood education centres have been found to exceed 140 decibels, which is louder than a shotgun.
Damage to hearing is irreversible.
"We find that people with hearing loss earn less, on average, achieve less, on average, they end up in jail more often," says Ms Seerup.
She says 90 percent of Māori in jail have some hearing loss.
It's not just in the classroom that children are exposed to too much noise, but in shopping malls, swimming pools and at cafés.
"I have seen a woman leave from the maternity ward and get her cup of coffee, and they put the baby in the one place nobody wants, and that's next to the coffee machine."
Some 50 percent of infant toys, such as 'Tickle Me Elmo' and 'Lullaby Glow worm', exceed safe noise levels.
Ms Seerup uses a Sound Level Meter app on her phone and leaves premises that are too loud.
She wants people to turn the noise down, and to be wary of the damage too much noise can do to young ears