Parliament's Speaker says his hands are tied over a decision that deaf Green MP Mojo Mathers must pay for electronic note-taking out of her own budget.

Ms Mathers is New Zealand's first profoundly deaf MP and she needs aids to fully understand debates.

She has a small TV screen on her desk so she can lip read but says the cameras don't always focus on MPs who are on their feet.

The Greens want someone to take notes which can be sent to her laptop in the chamber.

However, Speaker Lockwood Smith says Ms Mathers will need to pay the estimated $30,000 cost from either her or her party's budget, as he is unable to allocate extra money from existing budget appropriations.

"Staff time like that, or support like that, is not something I can just ask the parliamentary service to provide," Dr Smith says.

"I can't, under the law, simply say `forget about that, we'll just put a bit of money in from here or there'. It's something that I have to consult on ... before I seek to alter any of the staffing support for members."

Dr Smith says the parliamentary service and office of the clerk are working with Ms Mathers to cater to her needs.

They had provided software for her laptop, and were also looking into voice recognition technology for a note-taker.

Dr Smith will meet with the parliamentary service commission in March to discuss the issue, while parliament's appropriations review committee will look at the wider issue of how support is allocated to MPs.

"In the meantime, all the technological support that Mojo has indicated that she needs, we're doing our level best to provide that for her."

The Greens criticised Dr Smith's decision on Tuesday.

"Every citizen has the right to understand what's going on in parliament," co-leader Metiria Turei said.

NZ First leader Winston Peters says his party will contribute to the cost of the electronic note-taking.