Psychoacoustics of normal and impaired hearing and applications to hearing aid design and fitting

Lead Research Organisation: University of Cambridge
Department Name: Psychology

Abstract

In recent years many improvements have been made in the quality of hearing aids provided to hearing-impaired people. The majority of hearing-impaired people are now being fitted with digital hearing aids that offer great flexibility for tailoring the sound to best fit the residual hearing capacity of the person. However, even the best current hearing aids do not restore auditory perception to normal, and many users of hearing aids complain of difficulty in understanding speech, especially in noisy situations. Our goal is to make hearing aids work more effectively for hearing-impaired people, who constitute approximately 7% of the population in the UK. We also aim to develop ways of fitting hearing aids more effectively, so as to optimise the benefit to each individual.

Technical Summary

Hearing impairment affects approximately 7% of the population in most developed countries, including the UK. In the majority of cases, the hearing loss is cochlear in origin, and cannot be ?cured?. The main form of treatment is via the use of hearing aids, and this is likely to remain the case for many years. Hearing aids can improve the audibility of soft sounds, but they are still of limited benefit in alleviating the major complaint of hearing-impaired people, which is difficulty in understanding speech in noise. This is true even for digital hearing aids, which are now available on the UK National Health Service, and which allow many possibilities for the processing of sound. One major goal of our research is to improve the effectiveness of hearing aids by: (1) the use of new and improved methods of signal processing in hearing aids; (2) development of improved methods of selecting the type of signal processing to be used with a particular individual; (3) development of improved methods for fitting hearing aids to an individual. All of these require an understanding of the basic processes and mechanisms that underlie the hearing loss, and that is also a focus of our work.

Publications

10 25 50
 
Description Clinical "Dead Region" testing
Geographic Reach Multiple continents/international 
Policy Influence Type Influenced training of practitioners or researchers
Impact Diagnosing dead regions influences the fitting of hearing aids.
 
Guideline Title Specifications for hearing aids for use by the NHS
Description Hearing aid specifications
Geographic Reach National 
Policy Influence Type Citation in clinical guidelines
Impact The work has led to more precise and effective specification of hearing aids for purchase by the NHS.
 
Description Test for diagnosing dead regions in the cochlea
Geographic Reach Multiple continents/international 
Policy Influence Type Influenced training of practitioners or researchers
Impact The test has led to improved diagnosis of hearing loss and better fitting of hearing aids.
 
Description Charitable donation
Amount £225,000 (GBP)
Organisation H.B. Allen Charitable Trust 
Sector Charity/Non Profit
Country Unknown
Start 09/2015 
End 08/2018
 
Description Industry collaboration
Amount £35,586 (GBP)
Organisation William Demant Holding Group 
Department Bernafon
Sector Private
Country Switzerland
Start 06/2013 
End 06/2015
 
Description International Joint Project
Amount £12,000 (GBP)
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 09/2010 
End 08/2013
 
Description Newton Fellowship
Amount £98,000 (GBP)
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start 10/2009 
End 09/2011
 
Description Project Grant
Amount £30,899 (GBP)
Funding ID 560:CAM:BM 
Organisation Action on Hearing Loss 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2011 
End 09/2012
 
Description Project Grant
Amount £109,415 (GBP)
Organisation Action on Hearing Loss 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2007 
End 09/2011
 
Description Project Grant
Amount £109,415 (GBP)
Organisation Action on Hearing Loss 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2007 
End 09/2012
 
Description Project Grant
Amount £30,000 (GBP)
Funding ID 559:CAM:BM 
Organisation Action on Hearing Loss 
Sector Charity/Non Profit
Country United Kingdom
Start 01/2012 
End 12/2012
 
Description Project grant
Amount £258,000 (GBP)
Funding ID RG78536 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom
Start 10/2015 
End 09/2018
 
Description Research Studentship
Amount £69,642 (GBP)
Organisation Action on Hearing Loss 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2009 
End 09/2013
 
Description Research Studentship/Starkey Laboratories
Amount £69,000 (GBP)
Funding ID RG61661 
Organisation Starkey Laboratories 
Sector Private
Country United Kingdom
Start 10/2010 
End 09/2013
 
Description Rosetrees Trust
Amount £30,000 (GBP)
Organisation Rosetrees Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2013 
End 09/2016
 
Title Test for diagnosing dead regions in the cochlea 
Description We developed a simple test that can be used in audiology clinics for diagnosing dead regions in the cochlea. 
Type Of Material Model of mechanisms or symptoms - human 
Year Produced 2006 
Provided To Others? Yes  
Impact The test is widely used in audiology clinics around the world. 
URL http://hearing.psychol.cam.ac.uk/dead/TENCD.html
 
Title Tests of auditory function 
Description We have developed several new tests of auditory function that can be used in clinical audiology for diagnosis and for hearing-aid fitting. 
Type Of Material Model of mechanisms or symptoms - human 
Year Produced 2008 
Provided To Others? Yes  
Impact The tests have allowed more effective fitting of hearing aids and have allowed prediction of benefits from hearing aids. 
URL http://hearing.psychol.cam.ac.uk/dead/TENCD.html
 
Description Benefit of extended bandwidth in hearing aids 
Organisation Earlens
Country United States 
Sector Private 
PI Contribution Measurements of the spectro-temporal characteristics of speech, calculations of gain requirements at high frequencies, help in study design.
Collaborator Contribution Implementation of study design and running of subjects. Development of new speech test materials.
Impact A journal article is in preparation.
Start Year 2008
 
Description Bilateral comunication in hearing aids 
Organisation Phonak
Country Switzerland 
Sector Private 
PI Contribution Assessment of signal processing methods for use with bilateral hearing aids that can swap audio signals.
Collaborator Contribution Technical expertise and experimental hearing aids
Impact Some of the algorithms that were evaluated seem promising and may be implemented in future hearing aids. The work is ongoing.
Start Year 2006
 
Description Evaluation of a bone-conduction hearing device as a treatment for single-sided deafness 
Organisation Sonitus Medical, U.S.A.
Country United States 
Sector Private 
PI Contribution Comparison of a tooth-mounted bone-conduction device with a device requiring a pedestal implanted in the skull. Moore designed the study and analysed the results.
Collaborator Contribution Provision of devices, provision of research facilities, and running of subjects.
Impact An article has been submitted to a journal.
Start Year 2009
 
Description Evaluation of fitting procedures for hearing aids 
Organisation Starkey Laboratories
Department Starkey Hearing Research Center
Country United States 
Sector Private 
PI Contribution We have developed a method of fitting hearing aids with extended highfrequency response, and we have been conducting trials evaluating this method.
Collaborator Contribution Experimental hearing aids have been provided that have allowed us to conduct field trials evaluating fitting methods and evaluating the benefits of extended bandwidth in hearing aids.
Impact The method of fitting hearing aids with extended high-frequency response has given promising initial results. Further evaluations are being conducted.
Start Year 2007
 
Description Frequency Lowering for Hearing Aids 
Organisation Phonak
Country Switzerland 
Sector Private 
PI Contribution Evaluation of different methods of frequency lowering in hearing aids.
Collaborator Contribution Hearing aids programmed with custom software to implement different frequency lowering algorithms.
Impact Conference presentations.
Start Year 2009
 
Description Improving the perception of speech in noise 
Organisation University of Cambridge
Department Department of Engineering
Country United Kingdom 
Sector Academic/University 
PI Contribution Brian Moore is acting as a consultant on a project grant held by Dr. Richard Turner.
Collaborator Contribution Development of methods for separating speech from background sounds.
Impact Research is still in the planning stage.
Start Year 2013
 
Description Sensitivity to temporal fine structure 
Organisation Oticon Hearing Foundation
Department Eriksholm Research Center
Country Denmark 
Sector Private 
PI Contribution We have conducted a series of experiments assessing the role of temporal fine structure (TFS) to the perception of pitch and speech. We have also assessed the effect of cochlear hearing loss on sensitivity to TFS.
Collaborator Contribution Technical expertise and advice on experimental design.
Impact We have developed two clinical tests for assessing sensitivity to TFS.
Start Year 2007
 
Title Hearing aid fitting method 
Description A new method for fitting hearing aids has been developed. This method is especially suitable for new-generation hearing aids with a wider frequency range than previous hearing aids. 
IP Reference  
Protection Copyrighted (e.g. software)
Year Protection Granted 2010
Licensed Yes
Impact Cambridge Enterprise is exploring the further commercial exploitation of this invention.
 
Title Hearing aid fitting method 
Description A new method of fitting hearing aids (CAM2) has been developed. Evaluations of the method have shown that it is superior to the method that is currently the most widely used. We are negotiating with Cambridge Enterprise to explore the commercial exploitation of this product. 
Type Support Tool - For Medical Intervention
Current Stage Of Development Refinement. Clinical
Year Development Stage Completed 2011
Development Status Actively seeking support
Impact The fitting method has already been used on a small scale for some novel hearing devices. 
 
Title Sensitivity to temporal fine structure 
Description We have developed two tests for assessing sensitivity to temporal fine structure in hearing impaired people. This is relevant for hearing aid fitting and for signal processing in hearing aids, as well as for auditory diagnosis. The tests have been made freely available for download from our website. 
Type Diagnostic Tool - Non-Imaging
Current Stage Of Development Early clinical assessment
Year Development Stage Completed 2009
Development Status Under active development/distribution
Impact The work is on-going, so it is too early to assess impact. 
 
Title TEN test 
Description This is a perceptual test for diagnosing "dead regions" in the cochlea. These are regions with no functioning inner hair cells and/or neurons. The results of the test are relevant to the fitting of hearing aids and cochlear implants. The test has been incorporated in the audiometers of several major manufacturers. 
Type Diagnostic Tool - Non-Imaging
Current Stage Of Development Wide-scale adoption
Year Development Stage Completed 2011
Development Status Under active development/distribution
Impact The test leads to improved diagnosis of the underlying nature of hearing loss and can lead to more effective fitting of hearing aids. 
 
Description Film documentary 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Keynote/Invited Speaker
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I was interviewed and produced some demonstrations for a film documentary on the effects of hearing loss. This was initially broadcast by the BBC, and has since been broadcast in several countries outside the UK.

I received several emails congratulating me on my contribution to the film.
Year(s) Of Engagement Activity 2011,2012
 
Description Lecture Cambridge Philosophical Society 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Primary Audience Public/other audiences
Results and Impact 300 members of the publlic plus memers of Cambridge University from a wide variety of departments attended. There was approximately 30 minutes of question time after the one-hour talk.

Several people in the audience volunteered to take part in experiments.
Year(s) Of Engagement Activity 2009
 
Description Lecture, University of Third Age 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Primary Audience Public/other audiences
Results and Impact Avoer three hundred people, mostly retired academics attended the lecture. Many had a personal interest in the topi - hearing aids - and there was a lively question time after the talk.

Many of the audience volunteered to take part in trials of hearing aids.
Year(s) Of Engagement Activity 2010
 
Description Presentations to meetings of the British Acoustic Neuroma Association 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Patients, carers and/or patient groups
Results and Impact I have three presentations on the benefits of binaural hearing and the problems experienced when binaural processing is impaired to members of the British Acoustic Neuroma Association. Acoustic neuromas often result in hearing loss or complete deafness in one ear. The audience largely consisted of people who had acoustic neuromas and their spouses/partners.
Year(s) Of Engagement Activity 2015,2016
URL https://www.bana-uk.com/
 
Description Radio broadcast 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Primary Audience Public/other audiences
Results and Impact I was interviewed about various aspects of hearing, hearing loss and hearing aids

I received many emails from interersted persons.
Year(s) Of Engagement Activity 2008,2009