The DFG has approved nine million euros for the third funding phase of the Collaborative Research Centre "Active Hearing". What are the scientists' goals and how can their findings be applied in practice? An interview with Georg Martin Klump, head of the research project.
QUESTION: Mr Klump, what are you investigating together with Magdeburg scientists in the Collaborative Research Centre?
KLUMP: To put it briefly: how the ear separates sound from different sources when analysing acoustic scenes. This is only partly an automatic process that takes place at the various stages of the auditory pathway, driven by the stimulus. Processes that take place in the nervous system are also essential - during active listening and concentration on individual sound sources. We not only utilise the acoustic information, but also what we see.
QUESTION: Can you give us an example?
KLUMP: Let's take a typical conversation situation over lunch in the cafeteria. Several people are sitting at the table. As you listen, you concentrate on the person opposite you at the table. Your hearing automatically analyses the words in the ascending auditory pathway according to acoustic characteristics.
QUESTION: What does it detect?
KLUMP: For example, it determines where the different speakers are located by comparing the sound in your two ears. The auditory system also analyses the voice to determine whether it is a child, a woman or a man. And it uses the acoustic pattern to identify which word is being spoken. At the same time, higher levels in the auditory pathway receive information about the lip movement of the person you are listening to. This helps to understand what is being said. All this information is combined and analysed according to automatic rules.
QUESTION: So that doesn't require me to pay attention yet?
KLUMP: Exactly. However, other processes are running at the same time. These have to do with your attention to the person opposite you at the table. You have automatically separated the sound sources by analysing them acoustically. So your hearing system now knows: A child is speaking opposite you. Now you can - guided by your attention - emphasise once again in your perception what this child is telling you about their last school trip, for example. In doing so, the brain also supplements the parts of speech that were not perceptible due to the noise around you.
QUESTION: Receiving the third funding for a Collaborative Research Centre is not a matter of course. What questions do you want to clarify over the next four years?
KLUMP: The example of the conversation situation I just mentioned sums it up: we want to understand how hearing and thinking interact when analysing complex acoustic scenarios. We were very pleased that we were able to convince the German Research Foundation to fund the Transregional Collaborative Research Centre for this third funding period over the originally planned duration of twelve years. In the first two funding periods, we focused primarily on the automatic processes involved in analysing a small number of stimulus properties. Now, in the third and final funding period, we are focussing on how the auditory system separates the important from the unimportant stimulus properties. What role does the combination of different stimulus properties, including those from different sensory modalities, play? And how does attention control processing? With our joint research approach, we can combine methods from neurobiology, neuropsychology, psychophysics and a medical-physical modelling approach - and thus arrive at a detailed understanding of the processes involved in active listening.
QUESTION: To what extent does your research flow into practical applications?
KLUMP: In situations in which an important sound signal is masked by other interfering sound signals, technical systems function far worse than humans. You can think of several applications in which the findings from our research help to improve function. To name just one example: A hearing aid is not yet particularly good at amplifying the signals from a sound source while suppressing other sources of interference. The hearing system manages this with ease. It is therefore important to map the processes in the hearing system in the programming of a hearing aid. Our basic research can therefore support the developers of technical systems.
QUESTION: What impetus does the Collaborative Research Centre provide for research in the School of Medicine and Health Sciences?
KLUMP: The funding of the Collaborative Research Centre also distinguishes the work in the research focus "Neurosensorics", which is based at the new School of Medicine and Health Sciences. The success is proof of the new School's research performance in the evaluation following the trial phase. In addition, the work in the Collaborative Research Centre allows many bridges to be built to clinical medicine. For example, it will help to improve the care of patients with technical hearing aids. Here, the ENT departments of the Oldenburg clinics can work together with the researchers from "Active Hearing". There are also opportunities for collaboration between the neuropsychologists of the Collaborative Research Centre and the neurologists - with the aim of clarifying the cause of perceptual deficits more precisely.
QUESTION: Your vision: What do you want to achieve at the end of your research in "Active Hearing"?
KLUMP: We want to have understood something fundamental: How can the auditory system specifically process signals from individual sources through the interaction of automatic analyses and active selection processes, and without being significantly disturbed by the other signal sources? The knowledge gained will also help us in the "Hearing4all" cluster of excellence to develop better technical hearing aids. These will benefit people. And they make it possible to talk to each other and participate in our society even in old age.