Waikato District Heath Board is retesting the hearing of 377 toddlers after problems were found with the national newborn screening programme.
About 2000 babies are being checked nationally after the Ministry of Health discovered irregularities with newborn hearing screening at a number of district health boards.
On Thursday, Hawke's Bay District Health Board said it is recalling 747 children screened since 2008 who, an audit has revealed, did not have their hearing tested correctly.
A further 777 babies born in the past six months are also being called back for retesting.
Waikato DHB will finalise the number of babies for recall by mid-February and will send letters to parents offering a rescreen.
Audiology clinical leader Emma-Jane Ward said parents or caregivers concerned about their child's hearing should consult their doctor, regardless of any previous hearing or screening tests.
She said the chance that testing missed picking up a baby with congenital hearing loss was extremely low.
"We believe offering retesting to babies affected by the screening anomalies is the safest and most responsible option," she said.
It was found that screeners hadn't carried out the process correctly and professionally, sometimes screening the same ear twice, or one of their own ears.
There are about 110 screeners in New Zealand and eight were identified as not following proper process.
Those eight are no longer working as screeners.