A systematic evaluation of the acoustic CR ® neuromodulation treatment for tinnitus

Chief investigator

Professor Deborah Hall

Study team

Dr Derek Hoare
Dr Robert Pierzycki

Professor David McAlpine
Dr Roland Schaette
Bridgitte Harley
Priya Singh
Cherilee Rutherford
(UCL Ear Institute, London)


The Tinnitus Clinic
Adaptive Neuromodulation GmbH

Study period


Acoustic CR® Neuromodulation is a treatment for chronic tonal tinnitus. In 2012, The Tinnitus Clinic Ltd contracted a 100 participant clinical trial (randomised controlled double blind) to establish whether or not this treatment works under properly controlled conditions.

The trial was undertaken at Nottingham Hearing Biomedical Research Unit (BRU) and the Ear Institute at University College London and was sponsored by Nottingham University Hospitals NHS Trust.

This study systematically evaluated a new, targeted, sound-based device for tinnitus using a two-centre randomised controlled trial conducted at NIHR Nottingham Hearing BRU and UCL Ear Institute, London. We quantified patient benefit using a range of different validated outcome measures, but the main outcome was a change in self-reported tinnitus distress measured by a questionnaire. The trial was the first independent evaluation of the device.

The first results of the trial were expected in September 2013. Review of the trial by independent auditors, however, concluded that there had been deviations from trial protocol and lack of compliance with the manufacturer’s fitting instructions. None of these factors were individually critical, but, when considered together, there was concern that the results of the study could not be regarded as scientifically robust. It is therefore with regret that all the parties have concluded that the results of the trial cannot be published with confidence.

Nottingham University Hospitals NHS Trust and The Tinnitus Clinic were discussing a new trial on Acoustic CR Neuromodulation. However, The Tinnitus Clinic Ltd has since separated from the Brook Henderson Group. This now separates the clinical therapy arm of the Tinnitus Clinic Ltd. from the development, production and distribution of the Acoustic CR Neuromodulation product T30 Neurostimulator. The likelihood of a future trial being conducted in Nottingham is currently uncertain. Nottingham University Hospitals NHS Trust has disclosed to the Brook Henderson Group a set of recommended actions relating to what additional knowledge one would need prior to developing a new trial including feasibility research necessary to inform trial design , irrespective of whether Nottingham University Hospitals NHS Trust sponsors that trial or not. Nottingham Hearing BRU, Nottingham University Hospitals NHS Trust and The Tinnitus Clinic are very grateful for the time and effort of the participants of the original trial.

Q&A on RESET 2

Q: Why did the trial not lead to results that could be published?
A: We wish to clarify any misperception that the trial will not be published in any form. All the results have been uploaded onto ClinicalTrials.gov (NCT01541969) and will soon be publicly available. A number of articles are in various stages of submission to peer-reviewed journals and these report information gathered during the study that will inform the design of future trials. The limitations of the study set out in the above reports include inadequate specification of the Clinical Trial Protocol, particularly with regard to (i) device fitting, (ii) tolerance for pitch matching shifts and (iii) monitoring of research audiologists after training. Regrettably, these shortcomings in the trial set-up mean that the device was not tested according to manufacturer’s protocol. The results of the trial cannot therefore be regarded as a robust test of the efficacy of Acoustic CR Neuromodulation as currently used, and do not contribute to the scientific literature and debate in the way we, and our patients, would have wished. The study did not meet the criteria for publication as a clinical trial, but has provided important information on the scientific basis of clinical trials in tinnitus which will be published shortly.

Q: Does the device does not work or is dangerous?
A: The above decision does not have any relation of the actual workings of this device

Q. Was this research a waste of NHS money?
A. Independent tinnitus clinical trials of this kind are currently relatively uncommon within the UK. There has been significant learning both from this trial and the auditors’ findings that will be taken into future trials for tinnitus devices. This will position the UK more strongly on the Tinnitus research map.

Q. Can I be included in any new trial?
A. Yes, providing you fulfil the relevant inclusion criteria for participation

Q. Did you learn anything useful from the trial?
A. Yes. Our experience from the trial has led the Nottingham Hearing BRU and Nottingham University Hospitals Trust to make changes in how our clinical trials are set up, conducted and monitored and we have also increased levels of staff training and supervision. We are confident that future trials in tinnitus in Nottingham will conducted to a very high standard and that there will be no repetition of the difficulties experienced during the trial of Acoustic CR® Neuromodulation. Also, some of the data collected during the recruitment phase for the trial will provide useful information and this will be published to inform the design of future trials.

Q.  Why is the device not available on the NHS?
A. Currently the device is only available privately. The device could be made available on the NHS if Clinical Commissioning Groups or Hospitals chose to commission it. However, further evidence about its efficacy, costs and resource use are needed to enable the NHS to make an evidence-based decision about commissioning a new treatment.  This is the reason why further research is essential.

Q. Why did it take nearly a year from when the results were expected to decide that the results were not reliable?
A. The independent audit took time to be commissioned. Such reviews also inevitably take some time to complete a detailed investigation of the trial.

Q. Who decided that the trial results are not reliable?
A. The independent audit and an internal review by the Sponsor, Nottingham University Hospitals NHS Trust, both agreed that there was a lack of scientific robustness across trial results.