Severe hearing loss affects over a million people in the UK[1]. The World Health Organization (WHO) estimates that by 2050 nearly 2.5 billion people worldwide will experience some degree of hearing loss and at least 700 million will require hearing rehabilitation.[2] If left untreated, hearing loss can negatively affect education, employment, and quality of life, and increases the risk of dementia and cognitive decline[3]. Now researchers at the NIHR Nottingham Biomedical Research Centre (BRC) and the University of Nottingham are launching a new study, sponsored by the University of Nottingham, which will inform the most effective treatment for people with severe hearing loss globally (those with hearing loss greater than 65 dBHL). An article detailing the research appears on the University’s website.

Working with hospitals in the UK, the Nottingham-based research team led by Dr Pádraig Kitterick and Professor Doug Hartley, who are co-chief investigators for the COACH study (comparing cochlear implantation versus hearing aids in adults with severe hearing loss), will aim to find out what is better for this group of patients – hearing aids or a cochlear implant.[4]

COACH is the first study worldwide set-up to answer this question and could change the way patients are treated in the UK and around the world, according to the announcement.

The group of patients included in this research are those with hearing test results and speech understanding scores that fall just outside the range where they would be eligible to receive a cochlear implant on the NHS.[5]

Kitterick, head of audiological science, National Acoustic Laboratories, Sydney, Australia, co-chief investigator for the COACH study said: “The COACH trial is a landmark research study in the field of hearing loss and it will address an important question about who can benefit from cochlear implants. We are delighted to have secured investment to enable the NHS to deliver this important clinical trial, which will be led by a world-leading team of academics, clinicians, and scientists. But, more importantly, it has been designed and developed with patients living with severe hearing loss.”

Professor Doug Hartley, professor of otology at the University of Nottingham and consultant ENT surgeon at Nottingham University Hospitals NHS Trust said: “The trial will bring together the research expertise in the University of Nottingham and Nottingham University Hospitals NHS Trust, supported by the world-class research infrastructure of the NIHR Nottingham Biomedical Research Centre. 

“This is a great example of the UK and our National Health Service being at the forefront of conducting clinical trials to improve the lives of people with hearing loss both here at home and around the world.”

The costs of the trial are being funded by Cochlear Ltd, a global manufacturer of implantable hearing devices.[6] The company is not involved in delivering the trial, which will be run independently by NHS doctors and audiologists, as well as researchers from the Nottingham BRC and the University of Nottingham. 

Professor Gerard O’Donoghue, Consultant ENT surgeon at Nottingham University Hospitals NHS Trust, one of nine NHS hospitals taking part in the study, said: “We are delighted to be working with Cochlear, a global leader in the field of biomedical technology, to address issues of great clinical importance to the field of cochlear implantation.”

Involving the public and patients is a key feature of this trial. The research has been designed alongside a public member of the research team who recently received a cochlear implant.

Sarah Chapman, a member of the public with hearing loss who is working alongside the trial team for the COACH trial, said: “The COACH trial is so important because we don’t know how hearing aids and cochlear implants compare for people with severe hearing loss just above the current eligibility criteria for implants. 

“This trial, which is being shaped by people with severe hearing loss working alongside researchers, will provide evidence to fill this important gap in knowledge. Instead of best guesses, we’ll have best evidence to inform decisions about treating severe hearing loss.”

A patient research partners group will advise the researchers throughout the trial on aspects such as when and how to approach people who might wish to take part and what kind of information people will need and want to hear before taking part. 

Patients using the audiology services at Nottingham University Hospitals NHS Trust are among those who will be offered the chance to take part in the study. Nottingham is one of nine NHS Trusts in England and Wales taking part, and the others are:

Participants can find out more about the trial and how to take part in it by going to the trial website: The front page of the website includes a recruitment video which explains how they can get involved.


  1. The Royal National Institute for Deaf People (RNID) website. Facts and Figures.
  2. World Health Organization (WHO) website. Deafness and hearing loss. Published April 1, 2021.
  3. GBD 2019 Hearing Loss Collaborators. Hearing loss prevalence and years lived with disability 1990-2019: Findings from the Global Burden of Disease Study 2019. The Lancet. 2021;397:996-1009.
  4. National Health Service (NHS) website. Hearing loss. Published August 1, 2018.
  5. National Institute for Health and Care Excellence (NICE) website. Cochlear implants for children and adults with severe to profound deafness: Technology appraisal guidance [TA566]. Published March 7, 2019.
  6. Cochlear Ltd website. About us.

Source: University of Nottingham