“Snake oil science: using ‘mild deception’ to demonstrate the influence of placebo and patient expectation on hearing aid benefit”

Contact Name: Prof Kevin Munro

Contact Email: kevin.j.munro@manchester.ac.uk

Dr Kevin Munro has a background in medical sciences and obtained an MSc (Distinction) and PhD in Audiology at the University of Southampton. He also has a Diploma in Management Studies. In August 2002, Kevin took up the position of Clinical Senior Lecturer in Audiology at the University of Manchester and was promoted to Reader in 2005 and then Professor in 2011. Prior to this time, he worked as a clinical scientist in audiology and has been Head of several clinical audiology servicess including the Regional Audiology Clinic at the Institute of Sound and Vibration Research, University of Southampton. He has extensive clinical experience that includes the assessment and rehabilitation of hearing and balance disorders in adults, and the assessment and habilitation of hearing (including cochlear implants) in children. His research interests include paediatric assessment and habilitation, plasticity of the auditory system, and ‘dead regions’ within the cochlea. in 2001, the British Society of Audiology awarded Kevin the Thomas Simm Littler prize for his contribution to research in audiology. In 2008, the British Society of Audiology then awarded him the Jos Millar shield. He is involved in a variety of professional activities, was a member of the editorial board of the British Journal of Audiology and is a former editor of British Society of Audiology News. He is a former Chief Examiner for the British Association of Audiological Scientists. He will become Chair of the British Society of Audiology in 2012 after serving as Vice Chair from 2010-2012. He has organised many professional and scientific conferences including the 2010 annual conference of the British Society of Audiology.

Placebo effects— clinical responses associated with the expectations surrounding treatments rather than with any intrinsic property of the treatment—are wide-ranging and are recognized in medical research and clinical practice. Because of their importance, we examined placebo effects in a hearing aid trial using benefit measures typical of those used in clinical trials: speech in noise tests, sound quality ratings and overall personal preference. Our approach was to compare two hearing aids that were acoustically identical. However, we used mild deception and informed the participants that they were comparing a conventional hearing aid with a new hearing aid. On all of our measures, greater benefit was obtained with the ‘new’ hearing aid. Given the potential far reaching impact of these findings, we decided to repeat the study. Once again, greater benefit was obtained with the ‘new’ hearing aid. These findings have important implications for hearing aid researchers. They suggest a need for caution when interpreting hearing aid trials which do not control for placebo effects. This is highly relevant to the UK National Health Service which currently spends around £60m/yr purchasing hearing aids. Our findings also have important implications for audiologists and hearing aid dispensers. It is likely that hearing aid users with positive expectations are more likely to experience benefit; therefore, the manipulation of expectations potentially offers an additional tool to maximize real benefit for audiology patients.

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