Hearing impairment or other auditory function deficit in young children can have a major impact on their development of speech and communication, resulting in a detrimental effect on their ability to learn at school. This is likely to have major consequences for the individual and the population as a whole. The New Zealand Ministry of Health has found from research carried out over two decades that 6-10% of children in that country are affected by hearing loss.
Choose NO MORE THAN TWO WORDS AND / OR A NUMBER from the passage for each answer.
For what period of time has hearing loss in schoolchildren been studied in New Zealand?