A test which could have prevented hospital staff - who were checking the hearing of thousands of newborn babies - from screening their own ears was not used because it cost too much.
A Ministry of Health report into the scandal, which led to 2064 children being recalled for further screening, has recommended an alternative test be used.
The situation, which led to a delayed diagnosis of profound hearing loss for at least one child after the 10-month-old was recalled, was first reported by the Herald late last year when some screeners from the six affected district health boards were revealed to be testing themselves instead of the babies.
Yesterday, the ministry released a report into the screening irregularities at six district health boards where two screeners were found to have tested their own ears instead of the babies' ears.
A total of eight screeners had irregular results. Other problems with the newborn screening programme included testing the same ear twice on a baby, and screening one ear of the baby and one of their own ears.