Understanding and alleviating hearing disability: the contribution of natural behaviours

People use their hearing in all sorts of ways and in all sorts of situations. Our sense of hearing helps us to understand what is going on around us, and warns us of unseen dangers. Possibly more importantly, hearing is vital to social communication. For someone with hearing loss, their experience of hearing disability will depend on the mix of social activities they take part in, and the importance they assign to success in those activities. Very little is known about how such patterns of hearing activity differ from person to person, and between people with normal versus impaired hearing. Nor do we know whether using hearing aids changes the activities people take part in.
At a more 'microscopic' level of detail, people instinctively behave in certain ways when faced with challenges to their ability to hear. For example, if we cannot hear what someone is saying because of a noisy background, we typically move closer or turn one ear towards them. We know only a little about these behaviours. People with hearing loss face greater challenges than others, and they may use different behaviours, or maybe they could be trained to use more effective behaviours. Meanwhile, hearing aids are generally designed on the assumption that people remain static and face to face, regardless of the situation. This means not only that hearing aids miss out on the chance to take advantage of their wearer's natural behaviours, but that they sometimes undermine the effectiveness of those behaviours.
It is becoming increasingly recognised that in order for hearing aids to be more helpful, they must adapt to the moment-to-moment changes in situation which are part of people's everyday life. Furthermore, the clinical prescribing of hearing aids needs to take more account of each patient's individual lifestyle and activity patterns.
Our research will provide new knowledge and insights which can form the basis of future improved hearing aid technology and prescribing. We will do this by:
- Constructing a mathematical model describing how the acoustics of the environment, hearing impairment, sound processing in hearing aids and body movements all interact to affect people's hearing performance. To do this, we will carry out several experimental studies measuring how people move and change communication tactics when their hearing is challenged.
- Determining whether real-world hearing disability (and the relief from disability provided by hearing aids) is driven by isolated events which are crucial for the individual, or by a 'grand average' of events across time.
- Devising and testing hearing-aid fitting protocols which account for patients' insensitivity to acoustic changes.
- Developing prototype hearing aid technologies which exploit or support listeners' natural behaviour to provide benefits beyond those currently available, and evaluating them in the laboratory and in realistic conditions.
- Examining whether routine clinical data can support more individualised prescription of interventions for hearing loss. We will use a very large set of data accumulated as part of routine clinical care, which means the data are relatively loosely controlled. We will evaluate whether known relations are nevertheless reproduced. If so, we will then look for informative new patterns which might be used to improve the individualisation of treatment for hearing problems.

People use their hearing in complex and diverse situations. An individual's experience of hearing disability, and benefit from hearing aids, will depend on a unique mix of social activities, importance of success in those activities, and how much hearing aids help in different situations. It remains unclear how these factors interact to drive the experience of disability or benefit for the individual.
In parallel, little is known about how people use low-level behaviours to maintain satisfactory auditory communication, and whether those behaviours change with hearing impairment and hearing aids.
These knowledge gaps hinder advances in hearing devices and rehabilitation, which increasingly target specific acoustic environments and listening needs.
Our research will:
-Assemble a model describing how ambient acoustics, hearing impairment, hearing-aid signal processing and body movements affect hearing performance.
-Determine whether real-world hearing disability/benefit is driven by key events for the individual or by a 'grand mean' of activities.
-Devise and test hearing-aid fitting protocols accounting for listeners' insensitivity to acoustic changes.
-Develop hearing device technologies which exploit or support listeners' natural behaviour to provide benefits beyond those currently available, and test them in the laboratory and in the field.
We will also test the utility of routine clinical data to inform the prescription of interventions for hearing loss. Using a very large clinical database, we will examine whether known predictive relations are reproduced. A datamining approach will indicate whether other plausible patterns are present.
Overall, the knowledge generated will facilitate the development of hearing devices and device fitting processes which provide improved benefits by taking account of individual behaviour at micro and macro-scales.

We will seek to continue IHR's excellent track record of disseminating our scientific results and knowledge to wider communities (eg http://www.100yearsofamplifiedmusic.org/). In this programme we plan to deliver three non-academic impact goals: (1) increase public awareness of hearing and hearing impairment in general and communication behaviour in particular, (2) interact with hearing-device developers so that our science can lead to improved future devices that take advantage of natural behaviour instead of interfering with it, and (3) prepare the hearing healthcare community for the novel interventions and benefit domains which our research may stimulate.

To do this we will engage three audiences:
Public Engagement (goal 1): Our research will give new scientific knowledge of how people use their hearing, and how their behaviour is affected by hearing impairments or hearing aids. Our research will add to the wider public's knowledge of hearing. It will also encourage public awareness and discussion of just how important hearing impairment is as a health issue.
Industry Engagement (goal 2): Our results will be of great interest to the hearing-device industry, as both improving the 'situational awareness' of hearing aids and developing behaviourally-based hearing-aid algorithms are currently in focus in industrial research. We confidently hope that this programme will feed into improvements in future hearing devices, by identifying new phenomena which they can exploit or mitigate and indicating how hearing aids might be designed to deliver improved performance in specific types of communication situation.
Health Engagement (goal 3): We expect that the insights found in this programme will be of interest both to many of those with hearing impairment and to many health professionals in audiology and ENT. Though the results will not lead to an immediate improvement in hearing aids (but see Industry Engagement above for downstream effects) we expect that they will be of background benefit through increasing the understanding of daily-life hearing problems amongst healthcare professionals, and by raising awareness of the types of hearing device capabilities which are on the horizon.