Melbourne (Agencies): An Indian-origin scientist-led team has for the first time shown that hearing loss in humans can be restored. They injected stem cells from nose into ears of mice with deafness which improved their hearing.

Sonali Pandit and colleagues at Garvan Institute of Medical Research in Australia have claimed that the research has the ability to reverse or restore hearing during early onset sensorineural hearing loss in people.

Sensorineural hearing loss takes place when hearing cells in the cochlea lose their function. Frequently inherited, and usually starting during infancy, the condition could slow a child's development and lead to speech and language problems.

The team found that stem cells appear to release "factors", or chemical substances, that help preserve the function of cochlear hearing cells, without the stem cells becoming part of the tissue of the inner ear.

"We are exploring the potential of stem cells to prevent or restore hearing loss in people. The mice we are using have a very similar form of childhood deafness to their human counterparts -- except, of course, that mouse years are shorter. So a mouse will tend to lose their hearing within 3 months, where a person might take 8 years.

"We are encouraged by our initial findings, because all the mice injected with stem cells showed improved hearing in comparison with those given a sham injection. Roughly half of the mice did very well indeed, although it is important to note that hearing wasn't completely restored to normal hearing levels," team member Sharon Oleskevich said.

Adult human nasal stem cells were used in the study, as they are abundant, easy to obtain and unspecialised (so have the ability to self-renew for long periods, as well as differentiate into cells with a variety of functions).

Though the study has taken five years to reach at the current pedestal, the scientists anticipate that it will take a further decade at least for the findings to benefit people.

The findings have been published in the latest edition of the 'Stem Cells' journal.