People are waiting up to five years for a cochlear ear implant because the service is underfunded, NZ First's Barbara Stewart says.
The party's health spokeswoman has official figures she says show funding has dropped since 2012/13 with only a slight one-off increase in 2014/15.
That's despite waiting lists increasing by 15 percent.
"There are 176 people on the waiting list for cochlear implants, and with this number growing each year the government still refuses to commit any more funding to help clear the list," she said.
"Currently people are waiting between two to five years to receive an implant.
"This is unacceptable, particularly because of the positive impact cochlear implants have on people's lives."
Cochlear implants are electronic devices that replace the function of the damaged inner ear.
Unlike hearing aids, which make sounds louder, cochlear implants do the work of damaged parts of the inner ear (cochlea) to provide sound signals to the brain.