Spécialiste de la perception auditive à l’Université de Cambridge
Entretien entre le Professeur Brian CJ Moore, spécialiste de la perception auditive à l’Université de Cambridge, et Christian Lorenzi, chercheur en psychologie expérimentale et directeur des études sciences de l’ENS.
Brian Moore a reçu son BA en Sciences Naturelles en 1968 et son doctorat en psychoacoustique en 1971. Il est professeur en psychologie expérimentale à l’université de Cambridge en Angleterre.
Ses intérêts de recherche portent notamment sur la perception des sons, les mécanismes de déficiences auditives, la conception du traitement du signal des appareils auditifs pour la perte auditive neurosensorielle, les méthodes pour prothèses auditives , la perception de la musique et d’instruments de musique.
En 2003, il a reçu la médaille d’argent de l’Acoustical Society of America en acoustique physiologique et psychologique. En 2004, il a reçu le premier "Prix international" de l’American Academy of Audiology. En 2008, il a reçu le « Prix du mérite" de l’Association for Research in Otolaryngology et le prix Hugh Knowles pour Distinguished Achievement de la Northwestern University.
Le professeur BCJ Moore est membre de la Royal Society (FRS)
Christian Lorenzi : Professor Brian Moore, you are emeritus Professor at the University of Cambridge, and you are a member of the department of Experimental Psychology. Over 38 years, you have led a very active group, conducting influential research programs on hearing and hearing loss, combining fundamental and applied research. Every student or researcher on hearing and hearing loss around the world has read your book “An Introduction to the Psychology of Hearing” or “Cochlear Hearing Loss”. How did your interest in hearing science come about, and how did you get into the practical side ?
BCJ Moore : Initially, I was most entirely interested in fundamental research, in other words in understanding auditory mechanisms involved in loudness and pitch perception, masking effects, and speech recognition, and so on.
My basic ideas on temporal auditory processing, pitch perception and masking were developed in the 1970s. The interest in the role of modulation in hearing came later and was strongly influenced by other researchers all around the world. Later, in the early 1980s, I started to see practical aspects of this research, and people and companies started to approach me with potential applications. My first involvement with hearing aids actually started with work on a 2-channel compression hearing aid. I was approached by an electrical engineer, Roger Lawrence, to collaborate in the design of a novel hearing aid and to evaluate it. The evaluation showed that the hearing aid was very effective and it was turned into a commercial product.
As another example of a practical application, in the 1990s, I published some work where I pointed out that the model of loudness developed by the influential German psychoacoustician, Eberhard Zwicker, was based on some assumptions that were not correct, and made use of old estimates of auditory filter bandwidth that were probably inaccurate. I was pushed to develop a better model, and this led me to the development of a new loudness model, that eventually became a national standard in the USA, and is currently been considered as an international (ISO) standard.
In another example, in early 2000, I was approached by Nokia corporation to develop models of sound quality to evaluate the quality of their mobile telephones. As part of that work, we developed new ways of evaluating sound quality that turned out to be quite accurate. Nokia used these models to assess their phones and check their sound quality without the need for human listeners. Since then, modifications of that model have been used to assess the changes in sound quality produced by hearing aids.
Christian Lorenzi : Today, do you think that enough research effort is devoted to the understanding of hearing and hearing loss ?
BCJ Moore : No ! Clearly, the proportion of older people is growing, which means that there are more and more hearing-impaired people. Despite hearing aids becoming digital, they are not much more effective than they were 20 years ago.
Christian Lorenzi : Why ?
BCJ Moore : Because hearing aids still do not fix the most serious problem of people with hearing loss, namely understanding speech in the presence of background sounds.
Christian Lorenzi : Isn’t it only a matter of “audibility”, that is the ability to detect weak sounds ?
BCJ Moore : Certainly not. Hearing aids can partially restore audibility, but they do not have much benefit in situations where a lot of background noise is present. I think we need much better diagnostic tests of hearing going beyond the traditional audiogram. We also need to improve our understanding of how to use the results of these tests in fitting hearing aids and choosing the appropriate kind of signal processing in hearing aids.
Christian Lorenzi : How could research on hearing loss and hearing aids be encouraged and increased ?
BCJ Moore : Government funding bodies should set aside money specifically for research on hearing, hearing impairment and hearing aids. Moreover, I think there is a need for more teaching of hearing in universities. In the UK, teaching on hearing is fragmented : a very few universities teach audiology courses which include aspects of hearing. Otherwise, hearing is taught as part of Psychology, and students may receive only two or three lectures on hearing and audiology during their degree course. So there is not enough teaching, that might trigger an interest in hearing. More people with expertise on hearing should be appointed as faculty members. One could also imagine incentive schemes involving matching funds with industry.
Christian Lorenzi : How do you perceive the role of industry in funding research ?
BCJ Moore : My experience in the UK is that hearing aid companies are often willing to fund Ph.D. students on basic research, but they are not willing to fund postdoc students, probably because this is more expensive. One good thing is that there is reasonably good and free exchange of information amongst most of the hearing-aid companies, which is unusual for industry in general.
Christian Lorenzi : How do you see hearing aids in the future ?
BCJ Moore : I hope that hearing aids will improve in some very basic ways. One example is that, in my experience, when you program a hearing aid and then you measure what it is producing in the ear canal of the listener, there is a big discrepancy : you do not get what you should get. And this seems to be true of all manufacturers. This situation should be improved and the basic calibration should be more accurate. The second thing is that modern hearing aids have lot of different types of signal processing going on at the same time, and I think that the manufacturers have not been careful enough about the way they interact. So the overall result is that sound quality does not seem to be great, but it is hard to figure out why. I think the manufacturers need to be more careful in getting the different forms of signal processing to work together and to minimize processing artifacts.
Unfortunately, there are still things that hearing aids simply cannot fix. One example would be if a person has substantial loss of synapses or neurons in the auditory nerve. As a result, there is less precise transmission of information from the ear to the central auditory system. So hearing aids will never restore hearing to normal.