Testing deaf babies helps speech

By BBC News Online's Damian Carrington in Washington DC

New technology involving the insertion of probes into the ear can rapidly and cheaply detect poor hearing in babies.

The test costs just $25 (£15). Over half the states in the US currently insist on this testing but a new study is the largest yet to show that the procedure actually pays off.

The first six months of life are crucial

The study was conducted at the University of Colorado, and the researchers suggest the benefits arise because the first six months of life appear to be critical to language development.

The research found youngsters who are fitted with hearing aids and get other special attention as soon as possible go on to develop near-normal vocabularies and understanding of grammar.

Their ability to speak clearly often remains impaired but the Colorado team found three-quarters of deaf and hard-of-hearing children who get early help can speak intelligibly by the time they reach school age.

'Critical period'

Christine Yoshinaga-Itano led the study, which looked at 368 hearing-impaired children born in Colorado.

She said: "The urgency for early intervention is very high.

"Our research supports the existence of a critical period of language development in the first six months of life."

Her key findings were:

• More than 90% of children with poor hearing identified early develop vocabulary within the normal range in the first three years of life.
• Just 25% of youngsters identified later have vocabulary approaching the normal range.
• Since screening began, two in every 1,000 babies were found to hear poorly in both ears. One in 1,000 hear poorly in one ear.

Without testing, poor hearing typically goes unnoticed until about two and a half years old. Before that, hard-of-hearing youngsters may babble less, but otherwise they seem normal.

The research was unveiled at the annual meeting of the American Association for the Advancement of Science (AAAS) in Washington DC.