LONDON — The National Institute for Health and Care Research is funding a multicenter trial across 14 UK hospitals to compare unilateral and bilateral cochlear implants in more than 250 deaf adults. The study, led by Addenbrooke's Hospital and the University of Cambridge, will assign participants either one or two implants for comparison.

Under current guidelines from the National Institute for Health and Care Excellence, most deaf adults in the UK are eligible for only one cochlear implant. The guidelines are based on analysis suggesting that offering two implants is not cost effective for the NHS, and on a lack of evidence in the area. Participants in the trial must have become deaf later in life and cannot already have an implant. Once the trial finishes, the findings will be submitted to NICE for review.

Matthew Smith, an ear, nose and throat surgeon at Addenbrooke's Hospital, said the trial would extend to adults an option already available to children. "We know from giving bilateral implants to children that it can have a transformative effect on their quality of life and interactions with other people," Smith said. "Through this study, we can offer the same opportunity to adults who have become deaf, and understand the potential added value of bilateral cochlear implants, not just in terms of hearing, but also how they enrich quality of life."

Debi Vickers, a speech and hearing scientist in the Department of Clinical Neurosciences at the University of Cambridge, said the comparison was overdue. "Children routinely receive bilateral cochlear implants. These can provide three-dimensional hearing, enabling them to hear more naturally than unilateral, with improved access to sound and better engagement with society," Vickers said. "In turn, these will result in reduced social isolation, enriched communication, improved mental health, and better overall quality of life. Adults tell us, and I agree, that they should be given the same hearing opportunities as children."

Ralph Holme, director of research at the RNID, said: "It's wonderful to hear just how life-changing this experience has been for Janine, and the impact it's had on her quality of life."