She laughs, crawls and gurgles like other 1-year-olds, but Addison Blundell cannot speak or hear a word.

The Lower Hutt baby is the first known victim of a massive failure in newborn hearing tests, which has affected 2000 newborn babies nationwide.

Addison has congenital hearing loss, a condition that should have been picked up routinely within days of her birth. Instead her parents were told her hearing was fine, and the condition was not discovered until she was re-examined 10 months later.

"It was a clear result and we thought nothing of it," her mother, Kerrie MacKay, said.

In the intervening months, her development has fallen behind other children. She will require years of speech therapy and extra assistance that could have been avoided, or at least minimised, had she received help earlier.

Addison's father, Rawiri Blundell, said it became increasing obvious at the second round of testing in September that his daughter was deaf.

"She can cry, giggle, laugh but by now she should be saying, ‘Mama' and ‘Dada'."

The couple are not angry with Hutt Hospital, which missed their daughter's condition because of "human error", but said newborn screening needed to change.

Ms MacKay said information after the first screening was brief and unhelpful.

"I think as a first-time mother with a newborn baby, you are relying on the hospitals to give you the answers you need and tell you whether there is something wrong. I also feel it took them quite a while to pick this up."

Addison should eventually have normal hearing. She is scheduled to have a state-funded cochlear implant early next year and her parents are trying to raise another $50,000 to cover the expense of a second implant.

She will also have years of state-funded speech therapy to bring her up to speed with other children. "The support that we are getting now is fantastic."

Mr Blundell said he worried that other parents might have decided not to get a recheck. "There will be parents out there that have said, ‘No, it's fine,' but I am so glad that we brought her in again."

The Hutt Valley District Health Board was unable to comment last night, saying the person who tested Addison's hearing no longer worked there.

- © Fairfax NZ News