One of the former students, Whiti Ronaki, lost his hearing at age 3 after contracting measles. He attended the school (now known as Kelston Deaf Education Centre) from age 6 to 16.
He will speak about how physical and sexual abuse at the school still affect his life and wellbeing 50 years later. His evidence said children were smacked at the school for using sign language - a claim backed by several other students.
In 2013, a group of five former students at the Kelston school launched legal action, saying the institution failed to stop abuse between 1965 and 1984.
At the time, lawyer Sonja Cooper said most of the claims related to one teacher who no longer taught at the school. The teacher was investigated by police in 2011 but not charged, partly because of the difficulty in pursuing historic complaints.
A former student, James Packer, said at a previous commission hearing in September that he was abused by a teacher at the school between 1983 and 1987.
In an affidavit read by his mother, Cheryl Munro, he said he was smacked in the head, punched in the stomach, beaten for speaking sign language and even witnessed the teacher breaking another students' arm.
As a student he disclosed this abuse to his mother, who also made enquiries with the school, but was "always pushed aside".
"I was so traumatised by the teacher that I couldn't talk about the abuse for long periods of time or in extended interviews," Munro said.
"I still push clothes against my door at night to stop the teacher coming into my room and abusing me."
The hearings will also focus on abuse at Kimberley Centre in Levin, Templeton Centre in Christchurch, Porirua Hospital, Tokanui Hospital near Te Awamutu, Homai School in Auckland, and Carrington, Kingseat and Mangere Hospitals in Auckland.
Ruth Thomas, lead counsel assisting the commission, said one of the key differences in this week's witness statements were what she called "covert abuse", a form of neglect.
"This is things like the loss of someone's personal identity by the fact of being in these institutions.
"They were very routine and regimented and regulated so that people were herded from one place to the other into the meal room, had to eat quickly then herded in to be washed, sort of almost like a conveyor belt, then herded into the day room where people would just sit in stare, or snooze, or sleep. There was no purposeful activity."
The Royal Commission, which began hearings in mid-2019, is scheduled to make recommendations to the Governor-General next year.
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